PHYSICO-CHEMICAL STUDIES ON SOME
REACTIONS OF ANALYTICAL IMPORTANCE
( S U M M A R Y )
" l *^ j-^s-i
THESIS SUBMITTED FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY
IN
C H E M I S T R Y
By
MD. NAYEEM AKHTAR M. Sc. M. Phil.
DEPARTMENT OF CHEMISTRY
ALIGARH MUSLIM UNIVERSITY A L I 6 A R H
November 1978
, f % -»
o.
M i l l WPliO i i« III ' i M W ^ . K H X a t l M k *
Th© purpost of th« pr9$«nt study was to inv«Rtlgat«
th# phy«'£c<5*ch«?nlcal pmn€rrtl«s of the cnlour reactions
and to u t i l i z e tharo foi? tha chemical analysle. From tJils
point of view the follo^ving tlirae aspects of the colour
rsectiwjs h?v« b«sn f^tudltd.
This technlqua h'^s b@c»n usad for ttia ealective detection
of €0©© coKpounds (labia l) ar^ for th© s«!i:i<|uantitativ»
d@t®rQinati<m of c i t r i c acid, p^dimethylaisinobonzBldahydo^
£UGr088 and glucosa.
Th© r@fult8 obtained Indlci^ta liiat the colour* th©
length and th© direction of p^oveirent of th© boundary can b©
U8©d for detection. This i s i»n ?»dv»ntaci© of solldUatat©
spot»t©sts cine© nnly the natur© fnd Intan^iity of colour
can b« uaad for d©t«ction in solution*stat© tss ta . Th©
Itn'^th r»f th© colourad boundary forra©d at raaq»nt/«arapl©
junctltm d©p©nds nn th© conc©ntration, ftiat© and syraoatry
of tha diffu&lnq &p©cl©s a£ wall as subatrat©* Thlt
characterist ic of solid*atat© r©actlona haa baan U8©d for
th© a©ailquantltativ© analytla.
•ffiff™iliiff I mfl
(omp9unds
DtUetlon of roffipoundfi by capillary solid^tttt* fpot»t««ts«
»MMPM|WMM|«MM»
T«B», Dur«ti(m c olour at Dir«ctl(m Itngth of ('*(.) (hr) jufictldfi of boundajpydfnra)
raovontnt
»
Acidfi
>xalic 60 7
Btntdie , , , , U3»V
ilalic , , , , m ——^
r:al«ic »» , , tO-Y ——
Cinnemic •» , , !.y
f^al<Miic , , , , LO - •'>
AcJlpIe , , , , I.Y ^
Citric , , , , 0«oy ^—-
rsl lcyl lc •• », (h-ia
Tartaric ,, #, 'V!/3
niecinic ,» , , — —
Hlpporie , , , , LY —
Ase'^zble » , , , ?-y •—
Phthalic , , , , a»U3 • •»>
Qallle •• •• — —
Ainaric ft •• U3 —•
^ •7
<~
12
8
a a
n
3
15
15 6(G)
9 4(tY)
TH
1ft
lA
TH
I§iUjt.??ii» liftftttj^mail
c^ailtDtitids (Or)
Duration (hr)
Col<»ir at Junction
'Jr«a
Thiourea
t^Vtethyloree
i » 3 » 0 i b u t y l *
/ 4 l yH* ) l ou re©
?h0nylur0a
FJim<sJls»
Catechol
Pesorcinol
?yr93allol
p»Kltroph»m)l
r'hloroglu^inol
/xrabinoM
Fructose
a«lactote
80
ff f
f>lr«ction length of of boundaryCmra)
(novament
8Y
Y
^»Y-H
y
QY
GY
QY
V
D
Lp.y
BI
Y
'SI
^
2
4 9
6
6
2
2 4
11
5
2 2
&
2
2 ,0
T»bU - 1 . [i:entliiu«dl
4
COR^OUfUSs {Juration (hr)
Colour at junction
Glucoso
Lactoeo
Maltose
.'^9l9Zit0s0
Tucrosa
Hhsionoaa
Trahlost
Xylose
P^Anilnobanssl* dahyda
ICC
• 9
80
90
P»chlorc^®n28l» dohyda 32
P»Dl«a tf^ylaraino* bansaldahyda 50
Bw hyd roxyban za* Idahyda 50
P-hydroxybanzal» dahyda 50
o-nitrobanzaU dahyda 32
Dlraction langth of of boundasy()nfii)
ffiovanant
2
t *
• •
f t
• •
• t
*$
• •
• •
t »
• »
SI
tUBl
?Y
Bl
Bl
Y
3r
31
ya
Y-8
Y
0
ta
^m
4-
3.0
1.0
T,i
0,5
1.0
ta
4
ti
T«VanllUna ac J Y —— Ti
Y SB Yellow} L«B!.lght| GeGxreeni "Vorang©; 3«aright, l«l«d| VasVioltti
?»:''inl:i 3l«^'^lu0i N.Sl • ?:8vy bin®? ''Y « ?8le yllnwi 3r » 3rown
: ® towards reagenti <j « t3«fards substancei T.l w Thin ring
* Th® f i r s t l e t t e r refers to the colour at Junction smi second
to that tRihich aoves in boundary
:®sgentj
tv»*.:8thylur0Q • p»d ItB© thy I ecjlnobenz aldehyde (p*DAB) for acids*
!>>0A3 ophthallc acid for ureas end phenols. Dlphenylaisine hydro*
chloride for sugars and aldehydes.
6
Di h«»iyla(9ifi« ( ^ A ) r»actt with p-dlsHiti^ylboftsaU
d«hyd« (omtus) in th« pr«6fnc« of acids* On th« basis of
the rsaction protlucts and th« catalytic offset of the acid
the reacticm mechanism given in echen^s 4 and 5 has been
proposed. 1h© slow step (k.) i s the nucleophilic additicm
of unprfitoneted D?A on M» and o»protonated p»DAB. The
eu seciMent eliminaticm of testes i s a fast step (k^)* The
iminiufQ salt (P) i s i^ry reactiw end i t may <»cidise or
dec<«ipose to give dark colour products. The Kinetic reeultt
ape consistent with ^ e expreseion(7)t 1,< . the forraaticm
of the yellow product i s f i rs t order with respect to DPA
dliere K « ••*' ^ ''-——^ ^^
HlesHmtal analysis* ion-SKChange results and '^e intense
ab&oxbanct of the product ere consistent with the long
conjugated tysten of structure (u or a or S).
This test has been used for the detection of c i tr ic
acid with the following procedure. A few drops of the test
f^
( O P A )
N - H + H * Kl
N - H
( O R A M * )
\^-(/ \ \ _ C - H + 2 M * CH3
Cn3
K- CH3 OM*
( p - D A B )
H 3 ' H V /
( p - O A B M i )
P -OABH2* ' ' + OPA SLOW CH3
CH/2 \ = / i ; Z \ ^
CH
C
YELLOW IMINIUH S A L T ( P )
SCHCMB: - 4
FORMATION OF YFLLOW fMfNfUM SALT (P J
8
VERY ,o> Stow
C M 3 ' H ^ — ^ (
'
^
WASH I WITHCTHANa^ OR WATEK OR OMSO 1-CH3
CH3 WASH 1
WtTHeTHANoJ . M' ORWATCRORl
OMSO W
t
> VCLLOWISH GREEN (Q)
(»l
SCHtLMe-SfConiinutd)
9
^
1" ( I n ~ N C I )
CRCCN COMPOUND
(S )
CH3/ A = : / AH \ ^ COLOURLCSS COMP>OUM0(T)
SCHEM€'S
OXIDATION or YELLOW IMfN/UM SALT(P}
10
•ubstane* in •thanol or in d ie t i lUd wattr. 2»3 drops
of t\cj) and wS ratin baadt in tha formate f' rm wtra
takan into a microtast tuba and than i t wat placad in
boiling watar for ^-d minutaa. A poaitiva rasponsa waa
indicatad by the appearsnca of a daep colour on tha
rarln baadt. 3y this proct(*Jja only c i tr ic tdod) and
barbituric (yallow) acids glva tha colours, Dthar acida
diiich do not giva colour fncluda ecatic* adipie»aecoi^iCf
banzoie* boric* cinnanic.formic* fumaric^gallic.gluteiRic*
7i!dolyl»3»acatic* psleic* sialic* malonic* oxalic*phth8lic«
calicylie.succinic* tartaric end uric. The lirait of
idantifioation of citric ecid was found to bo ICyug. Tha
dataction of citric acid (?Oyug) waa raada in tha praeenca
of raimaining t enty ona acid*; succasafully. Thia r«8cti<m
ia ao sansitiva that 9ymn diluta vagatablaa and fruit Juicas
can bt taatad. Tha proeadura W&B triad with auccasa on
lasion* oranga and tseato Juicae. Tha tact waa aiada vdth a
drop of Juiea fr<» fraahly cut surfaca of fruita and
vagatablaa.
H-»»»
PHYSICO-CHEMICAL STUDIES ON SOME
REACTIONS OF ANALYTICAL IMPORTANCE
TH€SIS SUBMITTED FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY
IN
C H E M I S T R Y
By
MD. NAYEEM AKHTAR
M. Sc, M. Phil.
DEPARTMENT OF CHEMISTRY
ALIGARH MUSLIM UNIVERSITY A L I G A R H
November 1978
. •"',' • . • •v W i l l
T 2 1 5 1
Ref. No
CHEMISTRY SECTION ZAKIR HUSAIN ENGINEERING COLLEGE
ALIGARH MUSLIM UNIVERSITY ALIGARH-202001 (INDIA)
Dated ?!^%ahmr 25 •X??^
This io ti> cart ify t*tat t l ^ wjTk e!*'?diecl in
th» sccoispaoySfig ^ # s i c Is th« original W5rk of fi»
ccnciSdata -nd i s (*tiit**>i« f->r syfe&lssisjn for th»
ui^rd of ?h,Z» :::@3r*« In Cti^f^istry^
2 with tg> put on r*caxd ^ a t « ««ork of such
magnltudt W9uld not havo b«en poasibi* for a* without
th9 btn«vol«nt help and covop«ration that I was able to
avail of , from eoat of my colleagyes* taachera and
friends*
To Dr.siC. RdthQr«« tocturer. Chemistry recti<m»
2«H, Colloga of Engg. and Tech*, A,f^,U., Aligarh, go oy
^anke for the ciost Intant supervision through al l the
(Hiesee of tsy research. Hie illuminating guidance helped
me out of the inevitable iiapastoa ishich by no means were
few and enabled me to coisplete this thesis.
Pirof. Mohein Qureshi, Head» Cheoiistry Section, Z.H.
College of Engg. S Tech., Ul%U,, Aligarh, oiade available
t^ vm a l l the resoarch fac i l i t i e s at hit disposal. X had
nuesermis occasions to fa l l back on his help and to benefit
from discussions with him. I owe hiai my most sincere
gratitude.
I an grataful to Prof.Waeiur Bahaan, Hetd of tVitt
Department of Chenlstry, A.ivi.U., Aligarh for having
graciously pemitted the use of the laboratory of his
departnent.
Last but not tht I t t t t , 1 wish to txpMtt my
unqualifitd lnd*bt«dn*tc to ny senior colUt^u* Mr* All
MohMMiad whos« unflinching eo*oi»«ratlon by way of
•xtandlng for my u«« of s<»Bt of hit own flndlnga went a
long way by eaving ma many a troublaa.
Thanks ara also due to tha Unlviralty Granta
CotnBil8alon (India) for financial aaslstanca.
(l d. NayatiB Alchtar)
IR g , , P ic A T I o,J,
X wish to d«dic®t« thift hufii>t« vfCftk to
My Father
Mrs, Tthtr« Akhtar
E*y Son
l\x, Arsalaan r.loh3tiKned Akhtax*
"Thty alto mw who stand and waif*
Milton
I IZ 1X2
2V
V
VI
Qo^ r ^.m^
t l « t of Publication List of figuroe List of Rtacticm fchtnte t i s t of Tablts
.nf^F,T^. r„ 1, Qanoral Introduction titoraturo Citod
niApm r, n
VII
1 20
f^«lactiv» datoctioA of carboxylic acids* uraact !>hanol8»sugars and aldahydas and sviaiquantitativa datartnination of citric acid, p<»diBi0thylaeiinob«n8ald«hyda,giuco6«
spot-^sts .
Introduction Exptrioantal R«suits DiscusaijOn Litaratur* Citad
• • •
• • •
• • •
• • •
• • •
• • «
• • •
• • •
• • •
• • •
• • •
* • •
2U 25 27 31 ^
53
Tha RachanisB of tha colour raaction of diphanylanina mlih p^diowthylaiBinobanxaldahydf in acid nadit.
Introduction Etrparinantal Rtsulta Discussion Litaratura citad
55 56 58 61 67 79
( I )
VIII gtiA^m r U
^ fttBitiy and 8«ltetlv« r«8ln ftpot^ t«ftt for citric acid*
Introduction D(p6rin«ntal (Results Diseustion Literatur* cit»d
• • • • •
• • • • •
• « • • •
• t • • •
« • « • •
• • • • »
81 82 85 87 97 103
»©«?•»•
dl]
1L;ST OF ?ugtiCATOH '?
i* £^«l«ctiiw d»t«ctton of carboxylie acid«» uraat and phanola and ef»i<|iantltativa datarfsination of c i tr ic acid by capillary solid*ttata apot»tatta
Tilanta {Jn Prast)
3. A sansltiva and ealactlva raein tpot-taat for ^citric acid.
j^ikrochiiBica Acta (In Praaa)
3« Tha nachani&m of tha colour raaet ion of diphanyl* amina witli p^dintethylaiRinobantaldahyda in acid madia*
Aott* J. Cham* (Cosmmnieatad)
#«#«
(in)
i,mpfrmm^. Pao* No.
Im Pig^m •!• Traneport naehanlsm with contact lM»tMt«n tha solids. . . . /
2. Figuva *2, EfCact of tlma on tha absorbanca of p»»ductG and raactanta 33 C» .•• 5 2
3. Figura»3a Effect of toIvanta on tha abeor* and 3b. banc* of solution containing
D?A(0,01M), |>-DA9(C.CUtO and tcKl l tO a t 33**C.
4. Figura •4 . Tha plots of abeoxbanca against tioa for solutions containing varioua init ia l cancantrationa of OPA, poDAB (0,9f4} and athanolic irKEl) rit 40 t l \ end 430 naw . . . 6 5
5« Figura -d. Tha plot of logarithms of tha init ial slopaa against tha logarithna of th* corresponding Initial concentration of the solutions containing p*DAB(0.5M) athanolic HCl (IM) and variable aaounta of OPA, •*•
6. Figure •^^ The absorption apeetrun of the red solution containing c i tr ic acid
( i ail. of 7%), aodiun fomate( 1 ail of 2%) and acetie anhydride (8 a i l ) . . , , 102
»»*»
56
(IV)
hMLMjm£J2ssLmmmsi
?,»9ff,. g»
JU Scheie* JU M«chanise of th* irftactlon bttwttn pyrrol* and p»DAB.
2* Gchcma p, Hachtnltts 9f the reaction between reeorcinol and p»DA9 in the presence of acid.
10
11 3.
4.
5»
«».
'"cheise 3.
^chesse 4,
Sehetne 9*
Scheeie 6.
Struetore of th® dye obtained fron the reaction between diphenylaaine and glucose. ••» Fottaation of yello«r iminiufn salt <P)» •••
Oxidation of yelioiar iminium e«lt(P).
Decoeopooition of yellow irainiun 8alt(P}. . . •
13
68
69
r7^
•*««••
( V )
im Of TAPtgg
^IsJiflU ?M% m»
1. T«bl« <-!• Absofbifict(Ab) of ton* earboKylle acids with rtagtnt A in th» solution «t«^ St 410 tm and 33®C...
5. TabltN>2I. tepillary s-^lid-etatt 8P9t»t«st8 results of carboxylic acids with Flaagtnt A at 60''c (•!» rdcordad aftar 5 hr.j ••«
3, Tablt*ni Colour an6 length of tha bt>undsry ae a function of acid concan-txation at 60^c, . . .
4, 7ablt*IV» Colour and lan'sth of tha boundary aa a function of tima at 60' C. . . .
1 . Tabla 'V* Capillary 80lid*atat« apot-tasta ra^l ta of uraaa ^th aaagant A* at 60**r.
6* Tabla*V2. Capillary aolid*stat« spot»t«8ta raaulta of phanola with ^aagartt A* at wC c« • • •
7. Tabla^VZI. Capillary solld-stata tpo^taata raaulta of augara and aldahydaa with Haagant A"* . . .
8. T^la-VIII, Capillary solld»f>tata eoot-tasta rasults of sugart and aldahydaa of varying coneantratione with aaagant A* <at 8 0 % for auftra and 5 0 ^ for aldahyda), •••
(VI)
33
3A
35
36
37
38
39
A2
F«9ff ffa»
9* TabU •IX, DeUctlon of •ronatic aldthydts end sugars w i ^ H«agent A .•« Uk'
iO. Tabla • X. Eainlquantitativa datarmlnatlon by capillary solid^stata spot*tests. . . . ^5
n^knp\. ri;„;.«
11. Table • i . Initial rats data tsilth raspect to D?A. . . . b I
12>. Tsbta • 7, eiemantal Analyeas Rtsults, . . . 7 6
13. Table - 1. Detection of variouc organic compounds t^ltb Hoagent 'b*. . . . 3 8
14. Table • 3. Detection of sonie ealta with aeagent *b». . . . 91
Id* Table * 3. Detection of some acids with .leagent 'a*. . . . 9 3
16. Table • 4. Detection of some acids with
Heagent *c».
17. Table • d. Detection of some acids and eo@e other co«|>ound8 with Reagent *b* . . .
18. Table -* 6. Detection of some acids with Dowex l»x8 in the presence of ACgO.
» • » •
9A
95
96
ivrij
'^
colour rtactlons h«vt occuplod • kty position in tho
sroa of analytical choiRiatry. Thty can bo usod for the
dotaction and dotorraination purpoaoa oithor by uaing inatru-
taantal mathods or non-instruawntal siathods. Tha inatrumantal
mathodi «ra vary tanaitiva and spaclfic but thay lack
•io^llcity and rapidity and raq^ira a ekillad o^ratorfiriiila
tha non^lnatrunantal fsathods ara fast, sitspla and inaxpansiva
and can aaslly ba wsad for tha flald work. Howavar, tha
following lasa familiar aspacta of tha colour raaetiona hava
bean found to be of great intaraat.
(I) Capillary eolld*state spot-teste
(II) Kinetic and mechaniatie atudiee and
(III) Ion-exchange realn apot>*taat.
(I) t:ap|l,j| f,xy ft^l^dffiti^tft. iPfftfrtfltt'
There la a growing interest in the science of solid*
state cheniatry. Industrial applicative (cera8iica»
refractory, remant, art i f ic ial geni«> etc) of solid*atate
Chaniatry are well known(l). Recently a considerable
attention haa been paid to the area of the solid»atate
organic Chemi8try(?,3). nn the subject series of international
syflposia(4) have been organlead and varioua reviews(3,9,6,7)
have been published, ftudies on reactlena in organic aollda
3
havt tmich to offtr to Chvnlsts conc«rntd with synthttlt.
dattctlcm and d«t«nninatic»i, raactlon eiachenisn of th«
chamistry of natural proeossas. Tht following facta ara
raeponaibla for b o ^ qualitativa and quantltatlva diffarancae
batnaan reacf^ione oecuring in crystal a (solids) and thosa
in liquids.
(a) All tha i&olecula in a given crystal occur in <mly
a small nuet>ar of confomati<ms.
(b) Tha ga^iatrias relating dlffarant ffioleeulesf and tha
types of possibla intarmolacular approaches are lisilted in
the crystal Ivut not In other phases.
(c) Solid-state reactions are free from complicated
interactims due to the presence of solvent and their rates
are sloi».
Factors («) ami (b) enhance the specificity of the
eolid»state reactions and factor (e) makes then easy to
underatand.
FeigKS} shovved aone possibil i t ies of using solid-
state reactions in qualitative organic analysis. Voskrenskii*^
review on ''rolid-state reactions in Analytical Chemistry*
ceaipriaes the nature of analytical reactiona between solids»
the history of their origin, seme rules and technlgues for
4
carrying out th« functions, r«iultt of •olid*st«tt dotoction,
end th« posfibilitlof. of using solld-stato •nalyticsl
rtactlons fof qualitativt at wtll at quantitativ* analytla.
Tha folloiving charactaristlcs of solid*atata analytical
raactlona hav» baen raportad.
(1) Amongat ions of varliAile valency* the itm havlf^) tha
hlghaat valency reacts f irst .
(11} Amongst ions of sane valency* the l<m having tiie
higher atomic ntied er or atooilc weight reacts f irst ,
( i l l ) Chealeal behaviour of the aollds defMinds on their
chemical structure while their kinetic behaviour
depends on their physical structure and
(iv) All crystals do not have the taise chemical reactivity.
Various technii^es have been used to study the solid*
state reactions* The slnplest* inexpensive and versatile
capillary technique has been used to investigate po««der
reactions. For inorganic coaipounds a cos^irehensive review
regarding the transport mechenleai and the reaction steps
hac been reported byHardel(6). Solid*state organic
chenlttry has been reviewed by Cohen and Qreen(3}.
Qenerally organic nolecules are bulky end Irregulerly
shaped(3}. Therefore aelf*dlffusion in their cryatals la
vtry sloww Tht moUculet of <m« tolld ph«t« r«tch thot*
of a ••eond tolld phas* In ordtr for • raactlon to occur
by diffusion olthar at tho surfaco or via tht vapour. Thus
tha crystal structuras of on* or both of tha solids
Influanea tht rata of rtactlon* Usstogl t t al*(5,JlO) havt
studitd the rtacti(M)8 btt«»@an organic solids by taking
raactants In a capillary. Tht following staps are aasuntd
in ordtr tsi discucs tht irtchanism of tha capillary organic
po\;^tr reactions of two solid phasts M end U to give a
eolid ccMspound t3lx.
( l ) Tht exchange proctssts of particles at the Junction of
the two reactanta arwl the formation of the reaction
product.
(?) Transfer of the rolecules or l<»ie through the
interface I between the reactant M and reacti<m
product*
(3) Diffusion of the molecules or imis of the suA>8tance
U thrmigh the reactl<m product (voluae diffusion* or
diffusion via grain boundaries and defect crystals of
the reaction product).
(4) Reaction of the molecules or ions of the substance M
at the interface II with the reactant N to fom the
product.
6
Analogous reactions ara atsuatd for tha migration
of tha molaeules of tha subatanca N through tha raaction
product in tha tana direction ami for counter transport of
molaculaa and ions (Figure i}« Zf tha reactanta M and N
are colourless and the product fttMx i s coloured, the length
(thickness) of the coloured bcmndary will either ffiove in
one direction or in both directions* Ihe reaction kinetics
i s follonrad by recording Hie increase in length of the
coloured boundary «rith tisMi*
On the basis of results obtained fros this techniciue
the foroatica) of charge*transfer complexes has been proposed
for the reaction of solid picric acid «dth a nuR er of solid
hydrocarbonsCS). rlth the help of similar type of studies
riinghC i l l concludes that t^e diffusion at ^ e surface occurs
at a very fast rate tvhen the migrating molecules and
substrate isoleeules have the same sites and slotilar syimetries.
These unique characteristics of organic solid«6tate reactions
have been utilised for the analytical purporea by Uureshi
et«al.(12). They have described capillary solid-state spot-
tests for the detection of ao«e nitrogen compounds and the
seni^antitative detemination of diphenylanine with p»diiiethyl«
aainebensaldehyde(p»OAB). I have used capillary solid-state
M N ]
M
It
N ] M
II
-if' 12d M N
N. It
M N
M N
riG. I TRANSPORT MtCHANfSM WITH CONTACT BETWEEN THE SOLIDS
8
8pot>t*6t8 for tht stl«ctiv« dtttction of carboxyllc acids,
u£o«fi« phanola, aldahyitoa and aueiara* and for th« aasti*
quantitativ* dattratlnatlona of citric acid, p»U/\a, sueros*
and glucose.
Bving tha participation of various prodticts of
unknown corapoaition in ^a colour raactims the isaehanistic
studios based on ^ e IsolatiMi and identification of ^ e
products becoise difficult. Eecondly» ae esost of the colour
reacticms of analytical importance are very feet , the costly
equipment °stopped flow speetrophotoffieter" IG required to
follow their rate. Therefore, a few kinetic and mechanistic
studies of colour reactions!18) have been reported. In our
laboratory the colour reaction of p»di8>ethylamin<H3enxaldehyde
with diphenylaiDine in acid nedia i s being studied for the
last one dacade. p»DAB, Ehrlich's HeagontdS), ia a very
iffiportant colouring reagent » an indication of this i s given
. i t h 169 r.f .r«nc. . d^.lng only .1th c . l . r l » t r l e d . f x . ! .
nation are listed in the book of Vejdelek and Kakac(14).
Colour reactions of p*0/y9 have beetMM of great significance
because of the following applicationat
( i ) the urine of individuals suffering fr«MB SMM psychotic
i l lness contains KryptopyrroleC15) which i s known as'nauve
9
factor* by virtue of i t s vfttetion with p«DAB.
t i i ) for testing of l lvtr fUnetlont26), diagnosis, ai^
•stimation of datoxieation of alkyl banztnts and drugst
the datarmination of hippurie acid has bean raada with
f>«DAB and
( i i i ) p-DAB play^an Iraportant rola in diffarantlatlng
batwtan earum empticmsC 17) end trtia scarlat favar.
Amongst above raactions tha nachenism (fchana l)
baaed <m kinetic etudiasClS) ha« bean reported for the
reacti<m bet«»ee» various pyrroles end p*DA0 in ccid
solution 6.
The raechanisB) given in Tcheoe 2 based upon the
isolation of the product has bean reported for the reaction
between reaorcinol and p»DAS (19).
tike p<»OAB, diphenylamine is also one of the important
colouring reagenta* which ia uaed in aany oxidation*reduction
titrationa(20) and in determination of vanadiuntv), various
aidehydea(?3), sug«ra(24,25) etc. Oiphenylamine has been
uaed for deternining the (ruc€9roteins(?6) in the urine of
persons suffering frosi rheusratisau It i s of considerable
iaiportance in organic tachnelogyf^O). Oiphenylamine i s readily
aubjeeted to autoxidation or decomposition to give various
SLOW
H H
CMO CMOM
NH«t NMt|
P y * p - 0 A 8 H * •
H ON
FAST 1-U JJ-CM =::/^\:JMt|*H,0
SCHEMe-- I
MECHANISM Of THE REACT/ON BETWEEN PYRROLE AND p-DAB
1]
MejN-T^ y-CHO
HO R
M e 2 N - / / A - C H - / / y - O H
OH
r HO R
OH
^^z^-Q-
- H
• HO R
SCHEME"2
MECHANISM OF THE REACTION BETWEEN RESORCINOL AND p-DAB IN THE PRESENCE or ACID
12
products. Bowm of thv products srst dark grtsn frss
rfidieal{?7) <f»hM), dif^enylbsncidioe 9r«efi08)tdiphsnyl»
bsn«idln# vloUt(?8), <|iinold salt(?9) of (C^H^J^Ph) ,
T^»ph«nyl*p*!>Sfi«O€Min<mlnln«(30) stc. TVrus tht c(MBpltxlties
regarding the mschenistle studis® of P*DAS • dlphdnylsnins
rvactions er« epparsnt* A survsy of tho literature shows
that diphsnytamlns reacts with eugarst94,95) to give blue
products. A probable mechanism of ^ e reaction based <m
the isolation and identification of the final coloured
product^ Scheme 3) has been proposed by t otnooe and Nakanura.
It i s also knoim that 2 moles of dlphsnylaraine react ufith
0,8 to 1.3 fsolee of formaldehyde to give (31) N,N»M'.N'-tetra-
phenyldiaminomethanOt ^^^2^)3^2* " ^^ Dische reactlon(32)
deoxyribose i s degraded to AcCHtCHCKD ««hlch atteches to the
p<»posltlon of one of the bensene rings of dlf^enylanine to
form the teuco bast, (p-PhN HC H )2CHCH»CH .c. The Leuco base
i s oxidiied In air ^n4 stabilised by liMiisation. Then ^ e
LeucobSfe aiay add secnnd AcCHiCHCHD isolecule by crotonisstion
^r^ cyelite at the opposition of one of the ii^enyl groups.
About the chemistry of a«iines»earbonyl compounds reactlon(33)
i t has been reported that primary, secondary and tertiary eminei
can react with aldehydes and ketones to give different types
13
Q ip x-x* «-x
I
o V)
u
X - X + t-^x
W
K Ui
o O
12
o Q: U.
Q UJ
? a CD O
iu
UJ
»^
U. O
UJ Q: :5
UJ
O O
:D o
UJ
O Ui
CL
u
of products* Primary aninoa glv* Inlnoc. thoto ladnot
e«ii-bo i«ol«t«d and thty rapidly dac«Bpoat unlaea thtra
ia at laaat on* aryl group on tha nitrogan or on tha carbon.
Whan thara i s an aryl group, tha coapounda ara qaita atabla
and ara usually callad Schiff baaaaCi),
c • 4 mn^ —^ ^ r - —.2-^ - c -0 m
( i )
vAvtm sacondary amlnae raact with aldahy^aa and katonaa*
i n i t i a l l y I3,ri» disubatitutad haisiaminols ( i i ) form , and
i t i e posaibla to iaolata tham* Howtvar thay ara usually
unatablo and a siora etabla product i s aoinol ( i i i ) . Although
( i i ) can not losa watar to giva a carbon*nitrogan dtnibla
bond* if ^ara la an ex -hydrogan, than iMtar can ba loat
In that diraction in t^ieh a carbon«carbon doubla bond ia
foraad to giva an anaainaCv)
MRj Na- HRjt \ I ^ 1 ^
I I I OH HU^ OH
( i i ) ( i i i ) (iv)
- CH - C- > . C « r -I I OH (v)
15
Stcondary aialnv p«jrchlorat«s(34) react with aldahydaa and
kttonas to giva iminiuai salt«<vi)* Tartiasy eednaa ean
only glva talta ( iv ) .
. C . 4 ^ - C - X II I
il H R R (v i )
I hava i ropoaad a aachanlss for diphenylaoina-p-DAB
reaction In ecid madia. Tha moehanism i s baaad upon (a) tha
kinatSes of reaction ar«s (b) tha isolation end identification
of tha reaction products.
{Ill) imsm^hmm^mSitM.,mp^s$MX < In 1953 Bijifnoto(35} et .al . proposed the use of i m -
exchange reain beada in order to enhance the selectivity
and aenaltivlty of the apot-teeta. These teeta are governed
by l^e phyaico»cheaiieal propertiea of the reain beada such
as nature of the ion^exchange groupa» s i te of the cavit ies ,
ion exchange capacity etc. Therefore, an ion-exchange reain
spot test gives a very selective and apecific indication
that ia very helpful for the analytical work. In addition to
i t , these tests also have the following advantageat
16
(«) tht 6«ntltlvity of tht U t t i t yxy hi9h b«cauM
th« eolouMd tfiAcltt 1« edn««fitriit«(t on 7««ifi l>««il««
(b) 7h» colour in tho rt»ln phato i t noro ttabU • • i t
i s now tT99 fron tho aid* rtictions duo t» tho prottnco
of othor 9poci«t in tho solution.
(c) h siaiplo and inexpon&ivo eqaipnsont i s retiuirod.
(d) A somi^skillod invostigstor can sorve tho purposo*
(o) lon^oxehongo resin bosds do not caueo any sido
reaction in tho rosetion aixturo and
(f) Xon^exchango rosin boads csn oasily bo rotcovod fr<^
tho reaction mixturo.
In this diroction urork has been done in tho area of inorganic
(36,37,38) as «ifoU as organic chemistry, Tho survey of
literature shows that already known colour reactions have
been used for this purposo. Sorao older spot tests have been
nodified in order to increase their sensitivity and selectivity
by using ion-exchango resin beads. A few new colour reactiona
have been discovered(39). Xn tho area of organicC 40,41,42}
thesis try the ion^oxchango resin spot tests have been proved
to bo verssti le for the dotection(39,40) of phenols, amines,
aldehydes, hydrssines, snides, imidos, snil ides, n i tr i les etc.
and for the oatisMtion of anidos and estors(44). Sono of the
recently reported papers have been sumsrited below. Tsugi(42}
17
rtportad tht dcttction of ftl{l«l^yd«t with th» h«lp of
eAtlon-«xch«n9« t t M*II SS «fiion*CRGti«ii9o Mstn b«tdt by
using th« following procoduro. A fow drops of «n aquoout
solution of in aldohydo Is troatsd with 0.1% 2<>hydyailno»
honso^laiolo solution Ccma drop^^ imathyllcfitonoC one drop)
and f«w bssds (estlon exchsngo rosin In H* form)* Th^n ono
drop sseh of 0* l^ p»nltrdl>«nssndlaionlui» f luor^orstt snd
5^ potassluis hydroxldo Is sddtd* Ths dssp blus or ^ s
grosnlsh colouration on tho surfsee of the beads indlestes
the presence of aldehydes* Anlcn-exehange resin beads In Cl*
form are treated with aqueous solutions of 1^ 4*hydraslno*
beniene sulphonlc acid and an aldehyde solution (both 9r« less
t^sn I ml). Then one drop each of tetrat^enxldlne solution
and 3^ potassium hydroxide solutions are added. A reddish
violet or bluish violet or green colour on the beads confirms
^ e presence of aldehydes* Qureshl et.al.(43»45«46»47,48)
reported e considerable work (discussed below) on lon»exchsnge
resin spot-tests* An aciueous solutlon(43) of an aldehyde le
heated with a saturated solution of sodlua cyanide containing
hydrogen cyanide* milphurlc acid and cation exchange resin
beads In n* fom to give eyanohydrlns. The besds catalyse
the conversion of cysnohydxlns to carboxyllc acids and amionla.
the amsonla so forsied reacts with the beads In the K form
18
«Bhich i« now converted In NH '*' fpxm, Th« NK In th« r«tin
bftdfi Is dtt«ct«ci by N««sltr* • r«ag«nt. For tho dtttctlon
of «Bilnoearboxylic acid(46) and sulphur containing anlnoacidt
tha following proeaduro ia adoptad. To a faw drops of t«at
solution ona drop of iS^ potassiun pamuinganata solution ia
addad and tha contants art haatad in a boiling wai^r bath for
2*3 minutas. Than lon-oxchango ratin beade (in UB* form)
aro addad and ^« contants aro haatad again* Finally baads
ara takan out^washtd with derainaraliza4 watar, driod with
a f i l tar papar and traatad with a drop of Berthalot Haagant.
If a blua colour appaars on th» baads tha aoino acida aro
prosant. Amidaa aiui imidas (47) ara hydrolyaad to giva eorraa*
ponding acids and asnuonia by hasting with cation»axch«ngfir
rasin baads in the H form. As discuesad iA>ova ammonia
convarts tha baads in ^M^^ form and dotactad with Bar tha lot
Raagantt fCatonaa(l3) aro datactad by traating than with
4 to 6 ani<m exchtnga ratin baada in C * foxm and a drop of
1% othanolic solution of l»chloro»2»4«dinitr«baniona. In
thia casa violat purpla colour on tha baada indicsta tho
praaanca of kotonas. PUjinoto(49} has daacribad a vory
aonsitivo ion-axchango raain apot tast for tho dotoetlon of
fluorido. Boltan(SO) has dascribad a nathod for tha dataction
19
of M,&«P and hdlogtne. X hevo developtd 0 eentitiv* and
e«ldctiv« r t s in tpot<»t«6t for c i t r i c acid. I t s ' limit of
identification i s iOyug. Resin beads in formate fom and
acetic anhydride have been used ae a reagent. The reaction
lo eo oenoitive that even dilute vegetables and f ru i t
juices can be tested. The procedure was t r ied with succeae
<m Imisimt orange and tomato juices.
The results obtained are diecueaed in deta i l in
Chapters I I , H I and IV.
20
U P»P' Budhlkov «nd h»U» QlnftUlng^. PrinclpU of tolid Statfl Chemistry, 1963 Maclaren and Sons Ltd, London*
2* A,W.^l£8bor9or» Physics and ChoinlGtry of Organic Solid Stata, Vol.!. Intarecienca« flaw York, J1963.
3. B,D, tohan and Barnard S* Graan» Cham. Brit, i973» i , 490.
4. (a) Brookhavan National Laboratory, US, Organic Solid f^tata Chaesistry, (ad, G.Adlar) Haw Yorkt Gordon and Broach, 1969} (b) t!?(»ixii8nn Instltuta 9f ^eianea,l8rsal, 1970, lUPACi Organic J^olld Stata Chamlstry, Vol,2, (wit • v Cohan)« Lcmdont ButtaraMirtha, 197?i (c) Univaraity ef Ctrathalyda, Scotland, 197?. Saa alco I.e. Paul and D.Y, Curtln, Accts. than. 1\9M, , 1973, 6, 217.
9. a.P. Raatogi, J. Scl. Ind. aaa.(India), 1970, 29 , 177.
6. K. Hardal, Angaw. Cham, intamat. Edit. 1972, XX, 173.
7. F.t4. I angar, Chaw. Soc. Ravs. 1972, X» 229.
8. F. Faigl, rpot Tasts in Organic Anelysia, 7th Ed. Elsaviar, Anatardaai, 1966.
9. P.Z. Votkraaantkii, Talanta, 1965, JZt 11*
10. a,P. Raatogi and N.B. Singh, J. Phya. Chaw., 1968, 22t 4446 and rafarancaa eltad tharain,
11. N.B. Singh, Indian, J. Chaiu, 1970, ft, 916.
12. M. Quraahi, H.S. Hathoro and Ali Mohaimad, Talanta, W 6 , 21, 874.
21
15. p. Ehrlleh, KStdicin meh9, i90X» 15JU
14. j;2.V<tjdtttk andAKakac, Fazbraaktionar In dar Spaktro* photomatarlschan Analysa Organischa Varblndungan, 1969* X, n^-i93,
19. D.O. Xrwln, VU aaygan, H. Hlyashlta, and J.a,^*dja7* fJatura, 1969» 2M.» 81A«
16. S, Ohoeori, £!. Ogata, &1, Ikada, and S.Kira, Anal, Cham., 1975, 4£» W94.
17. J.K. Datta G^pta, and U.H. 5 8ha, Acta Cryatallgraphica, 1973, 2 i (6 ) , 1228-33.
18. Fl,S. Alaxandar and A.ru Suttler, J. Cham, Soe., Parkin II, 1976, 696.
19. B.&!. Aehe@9n and X. liirnar, J. Chromatogr.» 1962, 2i 520.
20. CO. Totalcak, Chamical Indlcatora, London, 1991.
21. ^. Hirano, H. r irayacia and 1. Kltahara, Japan Analyat, 1996, ^ , 7,
22. V.U Maaurio, Ann^Chan., 1913, 23L» 47.
23. fi«. Quraehi, I.A. Khan, Z. Anal. Cha»*, 1978, 289,282.
24. T. Momoaa, Y. Uada and M. fjakaoura, ChanuPharai. Bull* 1960, t , 827.
29. T. Moiioaa and tf.» Nakamara, Cham. Pharsi. Bull. 1962, l a . 944.
26, p.p. Yarovol, Lab.Dalo, 1969, i2» 792, through Cha«. Abatr. , 1970, 22t 98312n.
22
27. I,L, Fintr. Orgtnlc Chtmistry. Vol.1, 6th Ed. Tht English f.anguag* Book Soeitty and Longnan Group Ltd. p. 644, 1975.
7B, K. Srisranaa, Talanta, 1977, 2&» 31*
29. H. rtaland. Bar, §6, 3296.
3C, w. R. 8iiiaal, n, Rma, fC.S. r.idhu, !nd. J. Chatib , 1979, i a , 987.
31. A.C. Farthing and H. 8. Nicholson, Chain. Aba. 1979, ga, 70e23d.
32. V.C, Itard, P. ^mof and V. Vial, Bull, Soc. Cham. Fr. 1971, i., 2134.
33. J. £^arch, Advancad Organic Chamistry Baactions, Maehanian and Structuara, McGraw Hill Book Company, p. 667*^668, 1968.
34. N.J. Laonard and J.V. Paukstalis, J. Org, Chais. 1963, 2&> 3021.
39. M. B>iinioto, 6th Annual Maatlng, Chant. Soc* Japan Kajoto, April 4 , 1993*
36. M. Atjinete, Bull. Cha». Soc. Japan, 1997, JO, 93.
37. M. FUjinoto. ibid, 1997, JO, 283.
38. H. Kakihana, Y. Mori, and M. Yaaiaaakl, Nippon Kagaku Zasahia, 1994, 21, *»67.
39. M. Qurashi, S.Z. Quranhi, Anal. Chan., 1966, ^ » 1996.
40. A. Tsuji, Nippon Kagaku Zasahi, i960, £4, 1090.
23
4JU V» BodatnYmimwx^ H* Krison and S.Yorliif Anal* CHim. AcU. 1963, 2i» »85.
42. A. Tsuii, Nippon !C«gaku Zatahl, 1963, Q^, 9X9«
43. n.Z. Qur«8hi, U, 9, Rathi and ^. Bano, Anal. Chanu 1974, 16, 1139.
44. IkS. Qur«6hi, r.z.Cur«ehi and f.C, Flnghal, Anal. Cham. 1968, ;«0, 1781.
45. 5:.Z, Qurashl and til.n. aathl. Anal. Chaa., 197a,42tllS4.
46. r.Z. Qurtahi and ZzzatuIUh, Anal. Chici. Acta, 1977,
47. f.Z. Quraehi and Izxatullah, Z«Anal«ChaiQ. > 1977,?8d, 26a,
49, S.Z. Qurashi and Ixzatillah, Talanta, 1977, ^ , 529.
49. ti, Fyjiinoto, HU Makayaaa, U,ltt>, H. Yanai and T.fagu, Mlkrochlffl, ikCta, 1974, £• ^^
50. U a Bolton, EdNic. Chato., 1973, 10, 231.
»»»»»
C-ti AP, Tg R, „ j ;
SELSCTIVB DETGTTIOM OF CAR90XYL1C /CIOS.UanAS.PMB^OLS, ALD^YDES Af:D aTGARS mU SEf11QUA!ITimTIVB DETERMINATION OF CITRIC ACID, p-DK^BWYUMIMDSH^TZLaktDEHYDB.QLUrOSB AND f TROSB BY CAPILIARY SOLID-STATE S?nT-TESTS.
25
:bit«r«6t in solid* Gt9t« chenlstry Is growingC i»d).
folid»Bt8t« rvsetlons have nuch to offsr to chenists conc«m«d
«9lth synthftsli^enslysis* rtection mechanlEin or i^o chsisistry
of natural proctssts. F«i9l(6) has shown some poss ibi l i t i ss
of using eolldketat* roacticms in <|ii3litativs organic
analysis. Ibosa Includa hydrolytic and a{3!nonolytic cltavagast
ond dlsplactinont, ccndansatlon and rsdox reactions ^ a t occur
uAten organic enKBpounds are moiled or slnterad wil^ suitabla
reagsnts* p^'Dlmsthylaminobenzaldahyda (p»DAS)(7} i s a usaful
raagont in organic analysis* It givae coloured products and
also produces fluortscant cosBpotind6(8) in solution. p**DAB has
also baen usad for tha spaeific dataction of diph«nylaiaina(9)
in the presence of hydrochloric acid. The kinetics and
Bwchanisffi of this reaction in the solid state were investigated
later(lO). It i«as found to be diffusiwi-controlled reaction}
a coloured boundary i s fozned at the Junction of the two
reactants and the diffusing species i s Rh NH rC
It waa« therefore,considered tvorthn^ile to uae the
f«r«Mtion of a coloured boundary for the detection of organic
coBipounds in the solid state. The use of capillary solid-state
^ot>teata was reported recently( 11) for the detection and
26
stmiquantitativt d«ttmination of SOIM eolids. In ordaT to
bring out cloarly th« advantagtt and limltatlona of ^ l a
tachnlqua «oma nore fundasMntal work waa nocaeaary. Tha
I»res0nt work waa tharofora undar*takan to find out tha
optiamiQ conditiona for tha solid-atata apot*taste and to
extand their u t i l i ty by inveatigating the dataotion and
datarminatim of soma nora organic e«iq>ound8 auch aa carboxylic
aelds* uraasy phanols* aldahydaa and eugara.^
27
All tho reagents uead wn of BDH Analan gx»^9*
Intim&tB mixturoG of variable concentration of test'
Aibstancee or the reagents vMiro prepared with starch
unlees otherwlsa stated. Di|>henylamine hydrochloride
(D?AH) was precipitated by adding the concentrated
hydrochloric ecld In the boiling ethanolic solution of
diph^nylafBlne. The precipitate eo <ft»tained wee f i l tered,
washed with ethanol. dried at room teaiperature (33^ )«
po<»idered and stored in a coloured bottle. How DPAH was
ready to use i s a reagent* The following set of reagents
vias usedt
Reaoent A t An eciuiioolar mixture of p-OAB and J^Mothylurea
( for acids}*
aeagent A i An e^ilnolar iBlxture of p-&\3 and i^thalic acid
(for ureas and phenols).
Reaoent A t DPAH (for aldehydes and sugars).
J
A graduated capillary of 3 SHR inner diasieter for
capillary solid»etate spot*>tests, an electrically controlled
oven for heating and Bauseh and Losii Spectronic*2C colorlneter
for coloriswtrie studies were used.
28
M^tfrEtf til I 'tft itffilfffi In f yplrl liylta*
Tht 9r«duat«d capillary wat partly f i l U d with
raagent A or A» or A« by continuous tapping and tho aolld*
taet caaterial wae addad to tha opan and. Both artdt of tha
capillary ymr» closad with cottem plugs with ('*Paailed) or
tfithout funsaalad^) a further aaal of plaatlclna* !^oagant8
and taet mattrials wara usad aithar undrlad or aftar drying
for 9 hr in Btx ©lactrlcally heatad ovan at 60®r. Tha
unaaalad or sealad eaplllarlas WT9 kapt in tha ovan at a
raqulrad taeparatura. Four cofsblnatlona wtro taatadi
(1) undrlad matarlala In unsaaled caplllarlaa* (11) undrlad
atatarlals in saaled eaplllarloat (111) drlad eatorlala In
unsaalad caplllarlaa and (Iv) drlad siatarlals in aaalad
caplllarlaa, Tha colour* langth and tha dlraetlen of
iBOvaaiant of tha raagant/aaopla boundary aftar a daflnlta
Interval of tlna wara racordad.
Solld»ftatf dfttftlont
A l l t t l a of tha f^olid-taat material waa taken into
mlcreteat tube with several aig. of reagent and the con tent a
ware triturated with a clean glaaa rod. The colour developed
on heating waa recorded. For heating, the tube waa placed
29
in « watts- bath aalntained at 80^c for aldthydtt and uraat
and at XQO c fox caxboxylie aclda and cugart. Tha l i is it of
identifleation waa dataroilnad bv atarting with knoM) volumaa
of atandard aolutions of the confound concarned and evapo
rating then to drynesa. The eolid reaidue then mixed
intiaately with the solid reagent.
A drop of an d<|tieoua teat solution of acida or
ethanolio solution of aldehydee or 5C;?5 aqueous ethanolic
solution of sugars waa eixod with 1^ ethsnolic solution of
A or A« (freshly prepared)* The colour developed «i heating
waa recorded*
Squal volumea of a 0, m solution of the acida and a
!?( aolutiim of reagent Af both in SC|S aquewia ethanol* «^re
mixed and their absorbance waa recorded againat 5(^ aqueoua
ethanol*
gfBt<»lfr>tnfUYf tfftfgfflln«t|gn»
c apillariea containing a reagent and varioua C9ncen>
trationa of solid teat material (undried or dried materlala
in unaealed capillariea) were kept at required teaiperaturea
30
in tht ev«n. Tht langth of th« coloured boundaary fomwd
at tha junction wat rtcordtd afttr a dafinita intarval of
tina.
Capillarias containing tha raagent and tha solid
taat catarial oiara kapt in ^ e ovan at a raqutlred tatspa-
ratura for a dafinita pariod. Tha ooloure davalopad at
tha raagant/teat matarial Junction vmrn eonparad visually.
31
R s s y ^ T ,§-„
Results obtained ar« •unsarlttd in tabUs I*X.
The following Is the oarder of brightness of the
reagent/saaiple coloured boundaryi i i > l > i v > i i i , while
the order of the length of the boundary la iv;;^li>/i > i l l .
renBltlvlty i The coraiparative study of the testa shows
^ o t a test «^ich i s insensitive in solution stote can be
made eensitive by {Mrformlng i t in the solid state* Fox
exas^le the liiaits of identification for ci tr ic acid,
evDAS. p*hydroxybenaldehyde and o«>vanilline in the solutlcm
state are 10,OCC «g, 1/ug, ICO^g, and 1000yug, re6|>ectively»
while in the solid state are 70/ag, O.C4^g, Syug, and i:S/ug
respectively. For ^gars the sensitivity in the solid
state la 2*3 tiaws higher than that in the solution state.
(Table IX)
remiQuantitatlve determiytationUn capillary)t The results
obtained are given in table K* The sensitivity of c i tr ic
acid i« good, IC^ citric acid g a ^ a length of 1 «» and 75%
gave 12mm iht sensitivity of p-DAB, sucrose and glucose
i s rather poor* 1C% p-OAB, 10^ sucrose and lO^ glucose gave a
32
Ungth of 1 an, 0.5 Mm and 0.5 nn rfttp«ctiv«ly «^iU
10C?5 p»DA9, IC(^ 8ucr9s« «rid 100?{ glucos* gtv« 5 raai,
4 am and 3 nn resp»ctlv«ly* A plot of citric acid or
p*DAB or 9luco8t or eueroso conc»ntr«tlon vvreus l«ngth
of the boundary was linoar Iwt did not pass through
origin*
rm»n tht incr«»t* Jn tho longth of colourod
i oundary i s not suitable for t ^ sttsiquantitative datar*
minatiof), visual colorimatry offer© en attractive
olternate. For example* capillariea containing reegant
A« and various concentrations dfo-nitreteenialdehydetlCStaXOO^)
«i«re kept at 32% for 4 hr. The colour Intenaltiea of the
products forraed at the junction wee found to be proportional
to the concentration ofo»nitrobensaldehyde.
s I m
• • • • • • • *
o o o o o o o o
o
o cy « CM
CM ^ S o d o o* o' d o' ^ ^
if c
«•
S est
«
I I
at
O •4
«*
CM I. •4
i;
1
^ •o •-« i$
<o
SI
J!
«» b •H ^
M •
CM
M
•o -« j ;
•
tf> •o •-4 M 5 ^
t ' l
lA *? in KO
b b b b • 4 «4 »4 »4
S o c ^ <9D •4 -4 ^ «v
<*> C*> tf> ^
b b b M
•4 «4 4 coj c5 ^ 4 4 4 CM
o
• i5 4
• I ^ k ^ J$ 5
a.
CM
0-1
I
<
CM
K
8 i S
. «
_* CM
•^ 5 X
2 • 1 •
u
I
O CM
<M U
CM f ? U
CJ
> ^ I
f ••4
2
^ o
fiu hi «H 4*
u
u 5 S
c X
a: -
• a? 4u C fs 9 a- c '^ '"' 8 5 I § « S x* af ^ x' > 8
CM U
w %. U
o P
u
M I I
4*
c I*
u
^ u u
I 8 « 3 I 3 c
m
<
e • at
m •o U <
3
ca
CO
» •
4 »* Cvi
5 ^
o o
I
m
e
l e N
3
O to
• Si
e
19 • • •»
c D
ceei
^ O
<
> > >- S *5 * •»a « » j •^j
>• C © C
[ *& i I I ^ I I B I
w *a cj w I ^ I (fl <0 C4
i T t T I T I t T T
r r n i i j s i c j c a j j x i 3 c3a u u
i T4I I T I n T
> > iD >* > O > O 0 O
PI I I ' l " ' I-
T T T i I t H n t i
*-SSSSS!5<=°
I I I I I I 1 1 P I I I I I I I
i T t I I t I T T T
*•*•'" I I S I S*- 3
I I T
I I
i i I
I I »
I I T
I I " >• >• C3
I I a I I T
I I 3 I 5 0
111 I Is I I T
I I 3
*: 5 " u u a t»
s
i s s
3
I s
0 I
Is
^ t
c
8 c O x*^
§ (0 53 a U 10
8 r 9 "8 ri a f *
&
•0 e g A
^ 0 N
J 0
S A
M k
§
•?
s » V
0
%' t£ ** V
8* *
Q C ••
S s 9 tu
t: I
34
** * 5
u »J '•'
35
T8bl« • III. colouv and length of the boundary as a function of acid conoontration at 60^e*
No.
1.
2,
3.
4 .
%
KO
50
Si7
100
50
29
100
50
29
100
50
25
A«ld coneantratton
Citrie aeid
» » t •
Phthalic aeid
Sal icyl ic acid
* t t >
• t f f
Ualonic acid
• • t »
» t »»
c
0
0
0
6
G
6
G
0
G
OY
OY
m
c&
LG
L3
G
G
LG
la
m
m
- .
DM
mmm^
—»
• - *
- *
- *
«Man^
- >
- *
—
1
5
2
2
1
6
4
2
2
—
* obsarvationa racordad aftar 2hr.for driad material in unsealed capillary. Abbreviations same as in Table XI.
36
Ttl»l« • IV, Colour »n6 length of th« boundary as a function of tlmt at tcFc^
Acids
Tartaric
Citric
Malic
i:>hthalic
t*al€>ic
Sa l i cy l i c
MaliNiie
C
0
0
0
G
US
G
GY
CB
V
US
IQ
G
U3
LO
IQ
m
^
— >
- ^
">»>
^
mmmi^
—»
1
7,
d
2
2 3
6
3
Stata
— .
—
—
—
—
gJ
9J
c
0
0
LG
G
G
Q
LS
CB
LQ
G
L3
G
U3 LQ
LO
DM
—*•
•Hk*
- ^
— >
- »
- W M M ^
I
6
>JLO
8
8
8 2
>iO
9
stati
—
9J
9i —
—
9J
9i
'c^strvations for driad natarials in unsealad capillary* abbraviationa aa In Tirit>la XI.
o
m
4» C
to IB
D
e
1-4 •a
«
>'
s*
» ^
8
3 o
Z
o
I - I I t
I S
5 W-H
I t i
# < H I I
U I I
° I I
I J
t i i I
° I I
o >
M W ^ W ^ «© CO <V «»
1 i Tl I T T t i
S
o
»
o >* >• >• >• >• m o
CO -4
f<9
i
t
?2
CM e: U X X X
g ri g u u u
M « M
H, B" f w a '
luLl ^ b ^ b ^.-J
S S 9! ^ U
»4
9 9 >* i
• 8 « S ^ i
m
. s
IS 5 ^ 9
X ¥
a?! u
u 9
»-* >>
e
a.
fit. («
m • C 9
e M
"SI *
«4 t3 C 9 94 O
«M
N
if «M »
i u s
g
£
&
I • i
I c *
37
o «o
*
B «
I 'g
i
o a
e
!
M > I
4 I -
«
u
i
03 U
• 4
SI
u
u
e^
Si
u
t
m
n M cxe<j <M
T T T i T I >- > s
« ^ WIN «0 -^
T T n r I S S 5 § 6 5
I T t l t i
g g C >
S fe *" ^ S
O Ht m • *« <o
? ' L - I -
« u
••4
J 3
s - 1 J I - "
« o
«4
^ » • • ^
X • * ! * •
nT «
u
« i 4
* i 4
u i:
B J * «o u
#14
1 $ •H
ae ^
<•)
« M O
X «
u
1& f>4
S«>4 • •
«4 e
fi;
I H
8 c 9
t 3
C 3
^»
»«
c
CO
M M
e •
e e
i «9
> 8 > M
38
39
Tablt •VII. Capillary tolld^ttatt «pot«t«ttt r«aultt of tugaYs and aldthydta with Rtagant A »a
Compound
Arabinos*
Fjructoea
Galdctoaa
Qlucost
Laetoaa
Maltoa«
Ta»9>««> ratura
90 80
ICO
90
80
90
90
80
100
90
80
ICO
90 8C
100
90 80
90
9 nin r/x
•»
•
SmA
m
m
m
•
mt
TR
•
<m
Y
iTT
5»0 iBln
r/i ..„ •
Bl/TH ai/0.9
XLail
2.C
4 *
•
Vi
.
TH Bl
2?r •K
1.0
3.0
Duration 30 iiin rA
•
01/TR 01/1.0
Y(M).
fl*
Ml
•»
•»
,.p;i,,„ 3,0
••
<•
P) ),
m^
1 hr
<»
Bi/m
wt
4 »
«
M,l,
«
<w
81, 9.0
•
«K
2 hr
•
Sl/IH <*
m
«»
«»
r yp.i
•
-
BUM) Xo
•
Ta
«>
-
3 hr c/l
•
a?^TYX«
i »
«»
—
TA .
av
«»
•
•
48 hr r/i •
•
ai»Y,| TH
I, 81 1H
•
—
<•>
•
«•
*
«»
4
.T«»U «yilt (Cftn lnwitf)
^ 3 ^ ^ ^ 1 1?C nin 30 Bill Thr F p 515? i l l i r
M«l«alt08t 50
Sucroe*
Rhamnot*
Trthlot*
Xylott
80
ICO
50
80
100
50
80
90
50
80
90
50
80
100
«»
-
i »
»
mt
"»
Tft
m
-
o*
•
»
<m
<m
t »
•
TT ^
<»
C,5
2,0
<•
r.5
«>
«•
L pi TR
1
TH
11 TH
-
C'S 81.
«»
1.0
3 .0
•
8g 1.0 Br „,
<«
TR
u IK
•
.
«»
iJL
V
«»
-
-
1^ 1H
<m
3.0 4 .0
<«'
«
XCgL 4.0
<•
4 .
if
•
«>
II
•*
-
1 l l >
« l
«»
" ^
«»
« l
i l l
TR
«»
«»
t s i TR
<»
<•
4 .
m
<m
«»
t 81 TH
-
Ml
TR
-
m
Ta
«•
"TO
<*
^
41
ConpdOfidt 1 ]
beniald«hyd«
p»chlorob«n» zald«hydt
^dimethyl* eoilnobenzal* dehyd»
ewhyd70xyb«iw zdldtthyd« p»hydroiryb«n» Eald«hyd«
0-nitrob«iital« d«hyd»
{vnitrobantal-dthyd*
n.v«ni l l in«
ratur*
50
32
50
50
SO
' 32
32
50
5 ttin <^A
.
TH
1.0
«»
im
tR
«>
Isl
20 ffiin c / i
«»
TH
3.0
TR
0 , TR
TR
TR .,,y. TH
DtUNltiOfl 3C nifi
«
TR
4.0
TH
TR
TR
TH
TR
1 hr C/l
«»
TH
5.0
TR
0 IT"
TH
Y TH
TR
2 hr C/ l
«»
•m
«>
T^
0
175
TR
TH
3 hr C/X
•
•
•»
TR
0 TH
1R
TH
48 hr C/X
m~ -
<»
TH
0 TH
-
TH
-
* Obsarvations racordad for undarlad isatarials in unsaalad capiXXarlaa. Bl » Bliiai TR « Thin ringt Yt « Yallow tinga, N.Bl « Navy blua, PY* Pala Yallow, 0» orangat Bk><Blaek» Br>Broim Othar abbraviationa aana a a in pravloiia tablaa.
* Tha f i r a t la t tar rafara to tha colour at Junction and tha aacond to that which iBOvaa in boundary.
Haagant A*. diffuaaa towarda tha taat aubttanca.
42
Tabl* oVIII. Ctplllary solid*et«tt spot»t«ttt ratultt of sugaxt and aldtnydts of varying coneantratlont with Raagant A« (at B(rC for tugart and at 50^ for aldahydta. ) •
fonoounds
Fuq ay t
Arabinoaa
Fructoaa
Galectos*
Qlucost
Lactota
Melazitosa
Sucroat
Trahlosa
Xyloaa
/ l< i Y^fI «
p^aainobanzal* dahyda-
p-chlorotoanial-dahyda
icn H hr
c7i
•
-
-
-
•
TB
m
TH
p»diMthylaaino> X . bantaldahyda ^
1
g,,hf cTF
TR
X.0
•
ITo
Ta
TR
&I2 TR
Concantrat^ona l^
«»
TS
«a
<»
mm
-
TJl
••
TB
«>
<•>
TR
TB RJit.°JlL
-
TR
TR -
0.5
•»
fc;l""
•>
a»
TR
C.13? Ml hr
w
TR
«»
«*
-
-
-
«»
•
-
m
«»
2 hr
TR iiJ .i.i!!l
1.0 -
«•
4 »
« k
-
«>
TR
«»
-
SHI TR
43
T»bl« . VIII. (rnntlnu«J^
comppun^g
m»hyidroiiyb«n-«'
p^hydroxybtn* xsldthyd*
0»nltrab«ni6l-ci«hy<t0
p»nltrob*nialo dehydt
fVvanilLint
kon iSJut
0
, p.,.
TO"
1.0
q
2,0
- %
2.0
PPf^ftflKl^i^tlona
i%
c/T
,,,PX..,
••
. -
TH
c7x
G
0
TO
«»
0.1^ )4 hy C/T
«•
-
«>
«»
« k
2 hr
TR
• t
GY •m
«»
TR
^ f%»M]rvttions rtcordtd for undried natftrials in unetalad capillari«8.
Othtr abbraviatlons saaa at in praviwa tabl«t.
atag«nt h*, diffut*f towtrdt tha taat tubfltancta.
44
T«bl» »lx. Dftttetion^of «rotBatic aldchydts and sugars with aaagtnt A*"
Cc«p£»ufid eolation^.tata roactien Solid f t a f Rtaction Colour Idantification Colour Zdantification
limit (;jg) Hol t ijug)
f^Fm^%H A. 4fhY ij8t
p*sminobon2®Idahyda
p*chlorobonzaldehyd9
p*d ieia thy I ominoben* saldahyda
Dohydroxybansal* dehyda
p-hydroxybansal* dahyda
0*nitrobenzaldahydt
p»n1trobanialdahyda
0»vanlllina
fim^u > Arabinost
Fructoto
Galactoaa
Glucoaa
Hhaamoia
^urcosa
Trahloat
Y
6
VG
GY
SY
Y
Y
Y
31. V
Bl.Bk
G.Bl.
G.BI,
3l .Br
G.BI.
L B l .
9.
80
I
100
100
3000
400
ICOO
7,5
5.4
80
39.6
36.4
»C
100
Y
IG
Y3
LG
GY
tG
Y
Y
Bly
ai.Bic
L BU
IQ
Bl.Br
Bl.
Bl .
2
60
0.04
60
7
100
100
12
3
1.8
50
19.8
27
30
50
Abbraviationa sa«a as in praviout ti^laa*
5
8
a (8 U
S » C
g »
a fey
§
«
« 0*
c
IS
Sis'*;
O
• o
8 I
§ s •
«HI " ^ 15
1 ^0
* "Vf s O €0
o •
* •
o c? • C3
* o ^ "•-
S ift
* o
o N. €0
45
8 8 ^ S ^
§ I
e 9 e < < < <
w a c 3S? JSP
g ^ 8 8
a tl S S
•*«» 1 a •-« u ft. c- t9
46
P, 1 ^,f tf ^ § I 9n
p»0A3 foms chronogtns(6»12) with ur«a«(i3»i4),
phenol8(l5)» aBiin*t(X6) fttc. in th« pr«e«nct of acldt. Th0s«
chroffi09«n8(6»i2} hav« be«n us«d for their dtttection and
d«termination in solution* Tha conctntration of the chromogens
increases«ril^ hydrogen ion concentration* Therefore, these
reactions have been recocMaendedC 17) for detecting and
determining free KCl in gastric Juice and eiineral acids in
adultrsted vsrine. Acids under study forto chronogens miiStx
reagent A corresponding to a j ^ of 400-410 nm in solution.
The secpience of acids in order of their dissociation constants
(O) and Absoibanee (Ab) (Table Z) are t^e folLowings
(D) Psl lcyl lc) Hlppurlc) Qatlle) Cinnamlc) Benxoic
(Ab) ralieylic ) Qsllle > Cinna»ic> Hippuric> Benzoic
Dibasic acidst
(D) OKSHC) Maleic> Malonic> Phthalic> Tartaric >
iiltlon^**" FU«arle > Succinic > Adipic constants
(Ab) Oxalic> Maleic) Malonic> America Phthalic >
Tartaric > Succinic > Adipie»
These data show the general trend I.e. the chronogen
47
eonctntsfttlen usually iner«&s«t with th« hydro9«n ion
eoncentrstion* Th»r«fox«t th^st r«a6ti<ifis c«n b« ustd for
th* d«ttctlon and determination of aelds In solutions.
Ho5i«ver» tha spaclfie dataetion or datanninati<Mi i s not
posfibla as acids undar study hava tha samayiojax (400 •
410 na).
For solid*8t8te dataction of acids, mixturas of
p»DAB and diffarant uraas »ara triad. Of a l l the ureas
tried, tha t4»taethylurea produces the brightest colour et
e very fast rata. Therefore a lalxture of p«DA9»N»®ethylure8
i s used as the reagent for 8clds« Ureas and phenols ware
detected using p*DAB as the colouring reagent in the
presence of boric acid, fO fvO , trichloroacetic acid end
s Mie other oerboxylic acids l istsd In table I. The results
obtained in the presence of strong acid (KHSO ) v«ere leaa
informative than those obtained in 'tiie presence of iveak acids.
Therefore phthalic acid - p*DAB fixture i s chosen as the
reagent for ureas and phenols. Oiphenylanine reacts with
aldehydes (18) and sugara(l9] in the presence of acids.
However Z found that DPm reacts directly with the above
eesipounds. SO mm i s used as a reagent for aldehydes and
augara.
48
TabU 21 6ho»8 wh«n eoiriilnation ( i ) i t U8td» tht
. eufKlaty soiattiiMG inov»s in both directions. This nay b«
du* to th« surfaco isoitturt* With coodftination ( i i ) tht
cot<»irtd boundary istltt. In thif cast the chroifiogtn fomtd
^t tract t surface laoitl^re and owlts. A gap at the
Junction i t foxaied under conditions (i}» ( i i i ) and ( i v ) ,
osving to ^ e compact nature of the chromogen. Under
condition (iv) results are very reproducible ta^ereas
condition ( i ) i s easier to use* the colours are brighter
and the results are reproducible, but the direction of
moveeient of the coloured boundary depends on the anount of
sttnospheric moisture. I t has also boon observed (10) that
the coloured boundary moves from the substance with higher
vapour pressure towards the substance larith the lower vapour
pressure, the length of the coloured boundary depends on
the concentration (Table XZI) sise (Table V) and syiUBetry(2l)
of the diffusing species and the substrate (Table VSI). This
characteristic of solid state reactions can be used for the
semiquantitative detemination of the diffusing species and
the substrate and this has been achieved for ci tr ic acid,
p»OAB, sucrose and glucose (Table X). Results given in
table IV show that the length of the coloured boundary and
49
t N ifitftfislty of i t s colour Ineroftso with tlAO. Tho rosultt
obtaiKi*^ ififjiieato that tbo coioux* th« l o ^ t b mA tii«
divttctlofi of Btovonent of tho boundary o«n bo usod for
4«t«ction* this id an atfvanta^o of tho solid*stoto spot*
tost einco only tho naturo and intonsity of colour can bo
uetd for analytical f>urpo®asin golutiofi->tta^ toatt. Tho
{sothod(l»20) propoaod horo la aolectivo for tho dotoction of
ewipounda undor a^dy and i t can bt nadt isoro stlactivo by
koopln^ tho capillary for a longar titto at a particular
tocRporaturo} by diluting tho tost eubataneo and by performing
tho tost at diffortnt taisporsturos.
Thus in tho homologous sorios of phonolt* (Tablo VI)^
uroaa (Tablo V) and ea:iHboxylic aeida (Tablo IX) toattd oach
i&aift>or can bo diatinguiahed from tho othors on tho baaia
of thoao pr^ortioa* Of a l l tho phonola triod» catochol
givoa tho longost boundary, and tho phloroglucinol boundary
movos in tho oppoeita diraction to that for tho othor
phonola. Although catochol cannot bo difforontiatod froai
raaorcinol on tho baals of tho colour (Tablo IV), It can bo
diatinguiahod by conaidoring tho diraction of sievoMOAt of
tho boundary.
Siaiilarlyt aaongat tho uroaa (Tablo V) allylthiouroa
can bo dotoctod vary aoloetivaly on tho baaia of tho longth
50
Of tht boufidftry and i t t dir«ctiOfi of aovt««nt. Tablo II
8how« that tartaxle acid and e i ^ l « acid can not b«
diatinguishad on tha baala of colour alona» but can ba
diatinguiehad by tha length of tha boundary, aapaclally
whan tha raactlon tl»a is increasad to 12 hr (Tabla IV).
Table II shoivs that ondar condition ( l i i U tha length of
tha boundary can not ba used to distinguish salicylic acid
from citr ic acid, or malonlc acid from phthalic ecld but
dilution of tha oaropla makes the distinction poeaibla
(Tabla III) .
In tha cea© of sugera (Table VII) the eaneltlvlty
of tha taste can ba enhanced by doing ti)e teat at elevated
temperature and for long direction. At low teiQper8ture(50*^)
none of the sugars gives colour before 3 hr. At 90®C after
5 nlnutea only fructose» glucose, maltose and rhaanose give
yellow colour so that they can bo distinguished from other
sugars under study. After ^ hr. the coloured boundary for
fructose, naltose and rhSBmese sielta and for glucose turns
blue. Hence glucose can be diatingulshed selectively. On
the basis of colour trahlosa can be diatingulshed from other
sugar a as i t gives brown colour after 30 ninutes w^lch
persists for 2 hr. At 9C.1C0^. glucose and trehlose give
coloured boundries that aiova 6 and 1.9tMi respectively in
51
2 hr whil* for oth»rt tht coloured boundary rtnaint stand
s t i l l , lh«r«fort, 9luco8t and trahloet can ba dlatingulahad
from ona anothar as wall aa from othar sugars* Amongst
aldahydas* p<»hydr<»cyb«ntaldahyda(0) and 0«*nltrobansald«hyda(Q)
can bo distinguishad on tho basis of colour «^llo p-DA3
(5r»») and 'Vnitrobentaldahyda (?wm) on tha basis of langth
of tho colourad bmindary* Tabla V2II shows that arabinosa*
fructoso and xyloeo gav« colourad boundary oven at 0. i^
eoncantration @nd they can ba datactad specifically. It i s
also elaar that after 30 minutes at 0.1 percent concentratiw)
only fructose produces blue*black thin ring. Similarly at
C. 1^ concentration t»»hydroxy»bensaldehyde and 0-nitroben«al-
debyde can be distinguished fr«!i their p»i60s«rs» while i t
i s not so at IC^ coneentraticm. Further of the substances
tested, only fructose forms product with DP/W which gives
fluorescence in ^ e capillary.
I t i s also clear that the rate of reaction in the
capillary depends on (a) the melting point and (b) the size
and symmetry of the molecule of the diffusing species!Si).
For example, the leng^ of the boundary for phenols
increases as the melting point increases. The phenol
molecules (Table VI) are almost al l the same in alie and are
52
»ll anhydrous. 7h* awltln? points of allylthlourss and
i,3«dibiitylthloitr«a •«• vsry doss , but ths l,3»dilnityl»
thiourta laolsculs is biggsr in sits. Ths boundary for
Ollylthloursa dost not movs towards ths rsagsnt but that
for lt3»dibutylthiour«a doss.
53
LlTlRAilJRE riT]^
JU M.D. Ceh«n and 0«rn8rd S* Gr«ffn« Ch«a3.Brit.* 1973, 2, 490.
2. 61,0. Coh«fi and G.M.Z. Schmidt, B«ectivity of Solids* p. 556 Eieevi«r» Amstft:rd«m, 1961.
3. A. vmir€b9Tg9T, Physics end Cheaietry of tho Organic Colid t tato , Volurat 1, Int«r6ei«ncf»» N«w yox-k,l963«
4. R.P. Rastogi, J, Sci. Ind, a»s. (India)» 1970,22.* 177.
5. IC. Hard»l, Angaw. Chain., 197?, a t , 7»?7.
6. P. Falgl, Cpot Taeta in Organic Anelysia.^ 7th Ed. Slsaviar, Ais&tardam, 1966.
7. C. ^nxia . Anal. Chaai., 1956, 2fti 1321.
8. J.A, Sradlay and J. Grant, Fluoraacanca Analyaia in Ultra-violet l ight, drd. Ed. Cha{>man and Hall,London, 1943.
9. la. Qureahi, S,Z.qura6hi, Anal. Cham., 1966, ^ , 1956.
10. M. Q«r*8hi, r.Z.qura8hl, H.S.Rathora and All Mohammad, J. Phya.Chaau, 1975, 22.. H'^*
11. IS. quraahi, H.S. aathor* and All MohaumMid, Talanta, 1976, 2a. 874.
12. C.A. Stranli and P.R. Avar^all, Tha Analytical Chaniatry of Nitrogan and Itt compound a, ^llaywintazw •eianca, Naw York, Part II , 1970.
54
13* W, P7«s*nlus» B. Fr«s«» W. Schntidtr (^l«i2»«d«n»Q«r) H«fi« Tech. > 8fts*fu V03rti>ftg»vero«ff. 1972* Mo. 2831 99«63| through rhtin. Abstr, 2ft» "7^^^ (1973),
14. a,C. Hoe«nty and K.P. Flnnty, Anal, Ch»ra., 1964,
15. R.f-3. Acheson and I, Ibmtr, J. Chroma tog. 1962, 1»520.
16. a.H. Aloxandtr and A. a, Butler, J. Chefo. Soc.Park II 1976, 696.
17. riW. Van Vxk, Phara. l?t«k blad, 1929, 66, 101.
18. »• Qurashi, f.Z. Qurashi and £;«C«f:inghal, Anal.Chim. Acta, 1966, I t t 19S »
19. T£Ut<Hi«t Momoea, Yo Uada and K!&saru Nakeimira, Chem. PhariB, Bull (Tokyo), B, 196§, 827.
20. P.I. Voskresanakll, Talanta, 1965, i £ , 11.
21. N«B* Singh, Indian Journal of Chafnlstry, 1970, g, 916.
• * » * •
r H ^ P T p. i > lU
THE nzmmim OP THE COUSUH RGACTION OF oiPHam.-AMINE T^llH p-DIME1HYLAM3S«C33rJ2AT-DSHYDE TJ ACID KEDIA.
56
p»Din«^ylaB)inobenfal(i«hydl« (p*OAB) la an Inqyortant
ehronogtftlc reagant which has been usad for tha datactlon
and datarffilnatlon ot pyrrolee(i)» aulphur cofflpounda(2)»
primary alif^aticCS) and aroeatic aminaeO), hydrasldaaCs)
of earbOKylic acids* aniiina eaodyas. phanol8(3)»urea8(4},
and maprol»«fflat«(4}* Xt rtact© e ith priieary aminaa to form
colourad Schlff's baeaa. Tha laachaniero of i t s reaction
with pyrrolae(3) haa baen rocantly atudiad. Howavar, vary
I l t t la i s knoiM about ita raactiona with soeondary arotoatic
aminos such ae difHianylanino (0?A)«
Fai9l waa tha firat(6} to raport tha raaction of OPA
witti p»DAB in t«90 aantancoai "^irprisingty diphanylaroino
gava a poaitiva raaction with thia raagant (p»OAB)» tha
liaiit of idantification «at 0.6/^5. A colourad addition
product i s probably producad** Qura8hi(7»8) and eoworkara
atudiad ^ t analytical aapaets of thia raaction in eona
datail. Thair main conclusions aro t
( i ) tha raaction takas plaea in tha prasanca of strong
acids. (ii) It is a two stop raaction. A yallow colour ia fornad
initially which changaa alowly to a graan colour.
57
( i i i ) Th* gr««n colour Is Irrevvrsibly ddfiozt>«<l on
estlMi •xchang* 7«6in beads.
(iv) Tht roaction can ba used for tht spacific dataction of D?A by the rasln spot tast tachnlqua.
Tha DHichsnItffi of tha p«Di 3»0?A reaetion was studSad
In tha 6olid stata{9) by Qurashl end co^^orkars and a
probabla eiachanlss was poetulatad. HoMNivar no ayatviaatlc
atudy has baen r«|»ort»d for th« inechanisffi of this reaction
in the solutim state. Tha present \mxk won thorafore
urtdertakan to understand the * eurprioing* reaction of p*0A3
«»ith OS>A.
It ia a complex reaction giving rise f i rs t to a soft
yellow aolid which alowly turns green. An attempt haa been
made to characterize tha yellow and green pr<M3bct8 with the
help of !ll!H,ia end elemental analyaia and to determine the
true «rder of the reaetion. A probable machani B based
upon theae studies has baen propoeed.
58
t\op^f^p^^ f Th« Bauseh and Lonb 6p«etronlc*20 sp«ctro»
photoai«tftr and th« Ft$h«r Scientific Tbdrmestat wtx« Ui«d
for aptctrophoton*trie kinetic studlas. The absozbanc*
was aitasurad in a ona en cuvatta. Parkin*Clawr 6^1 Qrating
SpaetrophotoiBa tar for Ifl and Varian 60 mz NMH ap»ctr^
photomater for Hia a1»diaa war* uaad*
naaaantai All chanleals wara elthar B.l£arck or B.D.II,
Analaa. Tha DOHMIK 5C?.*X6 raaln baade In H*** form t^r« usad
for raein baada teata*
Kino tic at Hthanelie hydrochloric acid (its) wart uead aa
tha solvant. To calculata( 10) tha trua o»iar,n, and tho
rata constant,k, with raspact to DPA concantrati<m^
/ollowing aquation wae uaad.
miart V i s tha valoeity ( in i t ia l rato) of tha
reaction^k and n ara dafinad abova and C la tha concan*
tration (siolasf^) of tha raactant coneamad. In ordar to
apply thia procodura tha absorbanca (Ab) of tha solution
containing a snail aaioiint of DPA and an axcoaa of both p»DAB
(» al of IM in 10 Ml solution) and hydrochloric acid (IM)
59
t»38 r«cord«<ji wltli tint at 4:^ nn. A solution containing
^ tal 9t lI ip*DAB and S aiX of tha solvent was ustd as a
blank. Tha plots of (Ab) varsua tioa v»tr« madt. tht slo e
t dit ^ at tha baginning of tha raaction (for 2 hr) in
each case rapraeanta ttia ini t ia l rata (V) corraepondlng
to a particular conctntration, Ttm valuas of n and k
«etra cbtainad from tha plots of logarithms of thasa ratas
against the logarithms of thir corresponding init ial
concentrations of OPA« According to Laidler(10} tha order
t ith respect to CiMicentration ie kno«»n es *true order*.
( i ) Yellow product t To 3.0g of p-OAS in 100 ml
carbon tetrachloride (CIT) was added 1.7g of OPA (mole
ratio ?il). To this clear solution 7 ml concentrated
hydrochloric acid was added dropwise with continuous
shaking. A yellow precipitate was obtained. This preci*
pitate was filtered under suction* washed iteveral times
with CTT. and dried at room temperature (25**C) for 2 hr.
This sanple was used for NMa, IH and TLC studies. Instead
of hydrochloric acid» sulphuric or perchloric acida can
also be used to obtain the yellow product.
60
(a) Th« gmen pt^eipitite obttined by nixing tha
canctntrattd solutions of p»DAS (lOg) end DPA (5g) in
eth«nol (99 ml) in tho prvsonce of concentrated hydro
chloric ecid was f i l tered, «98ehed $»ith ethanol end dried
at roots tenperature ( ^ ^ } . The product so obtained
was ground (2g) and refluxed with ethanol (250 ml)
containing C,5 ml concentrated HCl for 6 hr. On cooling
the filtered green ethanolic solution for PA hr a green
precipitate settled do««). Ihe precipitate so obtained
was filtered* vs eshed tsrith ethanol and dried at ICO^.
Instead of hydrochloric acid, sulphuric or perchloric acids
can also be used to dbtsin the green product.
(b) When isq;»ropanol solution (95 ml) of p^DfiS (lOg)
end DPA (5g) were mixed in the presence of concentrated
perchloric acid, a green precipitate was obtained, the
precipitate was dried, ground and washed three times with
ieopropanol, dil.perchloric acid, ethanol, bensene and
finally with ether. To make the washing more effective the
powder was taken in a conical flask with a solvent and
shaken in an electric shaker for 7 hr. This process was
repeated with each one of the above solvents. The undissolved
portion was dried and studied.
61
ft E SU t TS
Th« t>8l l ti9n sp«ctra of tht r«aetantt (p-DAB and DPA)
and tht product solution In m athanoUc Hri wae rtcordtd as
a function of tliaa and tht rosuits obtalnad era shoum In
figuro 2. Tht t f f tct of ©olventa on tht abaoibanct of tht
rtaetion alxturt i s nhmm in ftgorta 3© end 3b. To calculatt
tht alopt ( **y'^' ) at tht btglnntng of the reaction tht plots
of absorbanet against tioJt for ytllow colour art shoiyn in
figurt 4, To calculatt tht trut ordtr 'n* and tht ratt constant
•k« tht plot of logarlthiES of tht Initial slopes against tht
logarlthaa of tht corrtsponding init ial concentrations of DPA
i s ®h&m in tablt i and figurt 5. The results of tht eltmtntal
analysit* UUR, TIC and IH art included in 'Discussion* stction.
Tablt 1, Initial ratt data with rtspect to 0?A.
r.No. C log C V log V
I 1 X 10-* .4,00 1.9X10'* *X71t U 9,i%l(r^ .3.6C 5 X 10"^ -3.30 III 5 x IC-* .3,30 7 x 10-* .3.1& IV 10x10-* ' .3,00 18 X 10"* -2.74 V 20x10-* -2.70 30 x iCr* .5>,52
C •> Tht init ial eonctntration (molts V^) of DPA
V « init ial ratt (tht slopt* ^ ^ y , ) whtrt Ab is tht absorbanct of tht ytlltw solution t f t tr tint t. p*DAB (0.5M) and IM tthantlie HCl wtrt used.
62
© DPA (<X lO'^M ) IN IM ETHANOLIC HCl JUST AFTER MIKING AND 2t HOURS
m p~DAB (<X lO'^M) IN IM ETHANOLIC HCl AFTER 15 MINUTES AND 2< HOURS
O REACTION MIXTURE CONTAINING THE ABOVE TWO SOLUTIONS (JUST AFTER MIXING) IN EQUIMOLAR RATIO
ABOVE REACTION MIXTURE AFTER 2^ HOURS
.--A-' .-A- A
0.0 360 <00 440 460 520 560 600 640
Wavelength (nm J riG. 2 EFFECT OF TIME ON THE ABSORBANCE
OF PRODUCTS AND REACTANTS AT JJ^C
63
0.25 -
0.15 -
0.05 -
O C o Q
O Q •5
-
-
IN ACETONE
' i l .n .
0 AfTSR 15 MINUTES • AFTER 24 HOURS
-
-
IN PROPANOL
• •
o AFTER 15 MINUTES • AFTER 24 HOURS
i'^^'-9-9=Q=9:St:3r9i2::1t:Pl9^
1.0 -
0.6 -
0.2 -
360 400 440 460 520 560 600
Wavefenglh ( nrr)) riG. 3a EfrEcr or soLvCNrs o/v TH£ ABSOR-
BANCe or SOLUTION CONTAINING DPA ( O.OiM ) , p.DAB (O.OlM )AND HCf(lM ) AT 33''C
0.55 r IN lEJRAHYDROfURAN 64
;5 2-00 r
}.60 -
f.20 -
(N GLACIAL ACETIC ACID
AFTER 15 M(NUTES AFTER 2< HOURS
0.60 -
O.AO -
0.00 9-0-0 9 g^iy"^"ajL^jLg 360 AOO 440 A QO 520 560 600
Wavelength ( nm)
FIG. 3b EFFECT OF SOLVENTS ON THE ABSOR BANCE OF SOLUTION CONTAINING DPA ( O.OlM ),p-DAB (O.OIM ) AND HCI (IM) AT 33''C
65
o c O
-Q
O
't:<0 -
1.30 -
t.20 -
1.10 -
hOO -
0.90 -
O.QO -
0.70 -
0.60 -
0.5 0 40 60 60
Time in minutes FIG. 4 THE PLOTS OF ABSORBANCE AGAINST
TIME FOR SOLUTIONS CONTAINING VARIOUS INITIAL CONCENTRATIONS OF OPA (I-lO^^M, II- 2.5X tO-^M, III- 5X}0-^M, IV- lOXlO'^M, V-20XlO-^M),p-DAB ( 0. 5M),ANO / M ETHANOLIC HCI AT 4 0 ± }°C AND 430 nm
66
Log. C rtG. 5 THE PLOT OF LOGARiTHMS OF THE
INtTIAL SLOPES AGAfNST THE LOGARITHMS OF THE CORRESPONDING INITIAL CONCENTRATIONS OF THE SOLUTIONS CONTAINING
O.SMp-DAB, IM ETHANOLIC HCt AND VARIABLE AMOUNTS OF DP A
67
D I s r u s 5 Iow
On th9 ba«i8 of th» x«scti^i products and th*
catalytic of fact of tho acid tha x« action tsechanlsm
givan in eehanaa 4>& and 6 may ba propoead. Tha alow
stap (k.) io tha nueleophlllc addltionk of unprot<matad
OPA on M*, and 0»protonatad p^Df-M, Tha subsactuent
elifninatlon of watar i s a fast atap (k^)* Tha yallow
Iralniun aalt (P) so obtalnad i s vary raactiva (schana 4).
Tharafora* i t may daeomposa into tha raactanta(echama 6)
or cay oxidlxa (schaoa d) to givo tha groan compound (a).
Tha raactants may oxidi«a i»ith air to giva colourad
product a {gehama 6),
Evidanca wil l now ba praaantod in support of tha
propoead isachaniam baaad upon kinatic etudiaa. MM: studiae,
in studiaa* analytical etudiaa and circunatantial ovidancae.
KinatH i;Md t.ti
Figura 7 shows that D?A is transparant in IM
athanolic HCl (at 33*V) fro* 360-6DC nn . In acidic
atadiuB i t oxidizaadi) to a blua compound slowly. In m
athanolic HCl p.DA3 abserba fron 360.420 mu It i s Known(l5)
that p-DAB foraa a N.protonatad compound with HBr. It ia
68
( O P A )
N - H + H * ^
Q/ N - M I H
( O P A H * )
n ,. CH3, ^ , OH
CH3. r-y. ?i , ^2 . ^ijr\'^^ C H - * / \ /
( p - D A B )
p - 0 A B H 2 * ^ + OPA
( p - O A B H l )
SLOW CHj
YELLOW IMINIUM SALT ( P )
SCHEME - 4
FORMATION OF YELLOW IMINIUM SALT (P J
6'J
CHj , , H J^~^
VCKV SLOW
( 0 )
CM/ M ^—^ CS M
^
^
^
C M , , j^ 0 /<n)
TiR T - « • MSO J
WASM I WITHCTMANOIL OR WATf R OR 0
WASM WlTMCTMANOLl OR WATER OR
OHSO t
- H \z=/
> VCLLOWISM GREEN ( Q )
M«)
SCH£MC-5 (Continued )
. > " < = \ / ^
1" (Zn~HCI)
70
y GREEN COMPOUND
( S )
^
COLOURLESS COMPOUND(T)
SCH£M€'5
OXiDATWN OF YELLOW IMINIUh4 SALT (Pj
71
| ( 0 )
OlPHCNYltENZfDINC (COLOUKLCSS)
DiPHENYLBtNZIOlMC ( V I O L C T )
^'
H*
QUINOIO SALT OP OIHHCNYLBENZIOINE (BLUE)
SCHEHC- 6 DECOMPOSITION Of YELLOWIMlNlUMSALTfP;
72
«l«o known that carbonyl group (12,13) g«tt protonattd
In acid madia. In aquaous solution tha pKa valuaa of
•NMaJFi'*' and *CH(OK)'*' for p<-OAB appaar to ba about 2.0 and
-3.7 raspactlvaly (on tha basis of tha llnaar fraa anargy
relationship). Isanadlataly aftar mixing tha acidic
solutions of p-DAB and DPA a yallow colour (P) Is (^tainad
«nd tha product absozbs fr«B 360-460 nia. On kaeping tha
mixtura for 24 hr tha yallow product Is convartad into
the groan product W corr*©ponding to ^gjg^ 620 niii. Iha
study of raaction in dlffarant eolventa (Figuras 38 and 3b)
©hows that tha yallow cooipouiid (P) changae to dlffarant
typaa of dark colour compounds corraspending tq \MW ^^^ " <
460 niB, 610 not and 610 nm In acatona, glacial acatlc acid
propanol and tatrahydrofuran raapactivaly. Thus It Is claar
that the dark colour product Involvas many colmireitspaciaa
glvan In schamas 4,5 and 6# Hanca It la alto <^vioua that
tha klnatlca of tha raaction can aasily ba folloiwad by
racordlng tha i^aoxbanca of tha yallow colour with tlraa.
Tha trua ordar of tha raacticHn has baan aiaanjrad at
40 ± i C and tha valuaa of n ami k with raspact to DPA
concantration ara O.gg and 1.738x10**a*^ raspactlvaly
(Figura 5), Whan DPA and ICl ara takan in axcaaa and p-DAB
73
1» dtfiel tf i t tht absoztoanett »««turti»nts «t 43C fitn ar*
found to bo orrofitous* Thoroforo th« tmo ordor hat not
boon dotorffilnod In th is eaao* An ettoaipt to dotomino tho
txuo ordor with roapoet to HCl has not boon suecossful
boeotiao tbo inciroaao In absoxbanco i t vory slow a t IOW/HV ,
whito i t i s voiry fas t a t higti /Ht/.
The slow atop i s tho formation of en addition
product, and free WPi roact© with W- and 0-protonetod
p-DAB, Tho l^»protonatod eorapound, «!*»ich »say bo predominant
specie a ie ascsitn&d to bo unroactivo. Frora the postulated
achemo ^ e foraation of the yellow product (P) can be
teiritten aa followst
4 1 ^ • k^ [p^um nfj^pk] (J.)
K| ia defined est
K^ • /DPAH*/ / ^PA7/H*/
The stoichiometric concentration of WA,[DPfKj ^^, can be
given by equation (3)
[DP/«*J* [DPA] • [^^]^i (3)
74
On substituting th* valu* of /DPAKJ in tq. (7)i wt 9*t
Kg i s d«fin«d at*
From o<^ation8 (l}» <4) end ib) aquation (6) can b« obtainod
(6) dM. h^J^^J^^l M^t
«*i«n J^DABJ and [M'*" _/©r« in axcess, oquatloM®) teducot
to (T).
dt
k Mhoro k at
^Kg ^DAvsJfH^J ! • K^^*7
Thut tha raaction i s f i rs t ordtr v/ith rospect to DPA and
i t has batn confiraad oxporisMntally.
In ordtr to find out tx^tthtr tht formation of tht
ytllow colour i s rovtrsiblt or not tht following studios
wart aiado« On adding conctntrattd KCl to tht ytllow
solution i t turns palt ytllow but on adding NaOH i t turn
75
y«llow «98in* Wh«n oort MaOH i s addtd th« solution
docolourlsot. On adding HCl to th is colourloss solution
i t turns yollow with tho 9*»»^8x ^^^ ' ^w*^ ** * par t ia l
proeipitaticm of the raactants. I t maans that tha yallow
ipacias can act ravtraibly aa an acid and a baaa. Tha
solution of the gretn product in concantxatod tsinaral
acids decolourisaa on passing nascant hydrogan« I t may ba
dua to ^ a foraati<m of a naw c^npoundCT). Thasa obsar*
vaticms suopoi't the poatulatad reaction GChama.
Tha yellow solid obtained, Is stabla for about 4 hr
at roflttB tatsparatura (25%). I t turns par t ly graan and
part ly pala yallow in 94 hr» In threa days I t turns bluish
gT99n and aftar many days I t bacomas graenish blua. Tha
yallow solid i s insolubla in C1C and bansana. I t i s s l ightly
solubla in mathanol, athanol and chloroform. I t i s highly
soluble in acatic acid and ramains yal lc^ at 25\, On
treating wil^ water i t becooea green and insoluble. In
dinethylsulfoxide (O ISO) and lainersl acids i t turns green
and i s highly soluble. TLC studiea in nathanol and chloro*
fom indicate that the yellow solid consists of dlphenyU
aaiinechloride (colourless spot correapcmding to Hf value l )
76
and a gr««n or blut product corresponding to Rf v»lu«
loro, la sptctrum of tho ytlLow solid in KBr doos not
contain >C«0 absorption p««k» Init i t shows a bro«d hump
fro® 3200-3600 cm"^ corrsspondlng to >tm or >^»^2 •
Tho mm ©psctruiB in tr lf luoroecetlc acid conslst t of
signals downfiald from tttraisttbylsilen© as ©.©.occurring
a t S« 3.06 (s ,? l l t ) , S» ^•IS (s,4?h54, S " 7.57 (J • 9H«,d,
J| C^H^), and ^ » 8.07 (J • 9HE,d.li C^H^). The NJIR spectrum
in deuteriated BWS.0 consists of the above signal and one
more signal a t S « 10 (sj^CH-). ttiese data Indicate the
yellow solid consists of coBipound(P) and DPAH •
The product obtained by using procedures ( I D s , gives
the analysis resul ts given in the lo t column of table 2.
These resul t s correspond to compound (Q) (ci"" is anion).
Ihe product obtained by using procedure ( i i ) b , gives
the analysis resul ts gl^mn in the second column of table 2.
These resu l t s corretpond to coeipound (R) (clO^ is anion).
Table <»2* Sleffiental Analysis aesults
Element
C H N
1st Colunn Calculated
%
64,95 5.67 7.51
2nd C< Experlnental Calculated
5* *
64.39 5.79 6.97
60.50 5.04 6.70
!>lu«m Experlmin
%
59.64 6.19 7,39
77
Th« femation of th» eoi^mtnd Itltt (^) h»» bt tn
(^s»]rvtd In the C8«« of b«fte«l<lthyd«»D?A reaetion In
tht prosofict of p«rehlorle acldCi^), Conpounds (Q) and
(a) are insoluble in C1C, benxono and chlorofowB. Thay
ar t s i l l i l y soluble In a d d l e mefhanol and ethanol and
reasonably soluble in DEO. Ihey tum blua in polar
aolventa such aa methanol* ethanol* DMSO, mineral ecids.
The conversion of the %T<»«n iolld to the blue tolld in a i r
i s tenpereture eensitive, i , e , at lot»er teii|>erature (C-20 \ )
i t reaains green and at high teaperature (above 30®c) I t
tuitia blue. In acetic acid they \^ and a) reaiain green.
Ho$«evert compound (Q) i s les t atable than (H). For example
a t 30% (Q) rapidly changes to blue ^\X% (R) turns green
slowly. la spectrus) of (H) in KBr eoneists of a strong
broad peak fro© 1700»i800 cm*^ corresponding to)C«0. No
aolvent was found suitable for NMB of (R). However i t a WMH
•pectxuai in tr if luoreacetic acid coneit ts of signal* a t
S» 3.5 (»,?Me 5, at 8» &.8t (huiBp* NH), and a t S * ' '•5
(a bread peak, 2Ph & ^^A^* Solubility in tr i f luoreacetic
acid «ras also poor. The green product does not tselt but
sublines on heating. These resul t s are in good agreement
with ^ e postulated sMiehanistt.
'^^^S'f
78
Li t ircuatttntUl •vldiic« and Uttrfttur* guoporti
Beth tht yellow and gr««n colours aro adsosbtd on
cation axchangt rasin baada tfihich Indlcataa a positlva
eharga on thaaa apaciaa.
titaratura supfiort for the abova maehanlsm ia provided
by the fact that pyrrolidine perchlorate has be in found
to react vdth bansaldahyde to give the ternary Imlnliin
6«lt(l4}*
' 6 ^
H
and pyrrole(d) glvee condensation product with p*DAB In
acid fsedla (eehente 1). Like (Q), (H) and (S) coispounda the
varying dngf of protonatlon has be<m reported for crystal
v lo le td l )* The dark colour of these coonpounda la
conslatent with the long conjugated systema of atructurea
given In tchei^«5''
79
E.ni.Siiii f» JBii B Si,i.Hi.i,(f S M I S
JU p. Bhrllch, {itediein Wocht, 1901, 151.
P» tf.H.P«Ash«»orth« Th« Dtttxtnination of f^lphur containing groups* Acadtmie Pro s a •London* Vol./>fX976«
3, F* Faiglt Spot tosta in orgi^nic Analyala* Elsoviar* AmetArdaiR* 7th edition, 1966.
4« CA. Streuli end P.a* Av»rati«a ' Tho Analytical Chtmietry of Nitrogan and ita coiap unda**. i;il«y>-Zntaracianca* Now York* Part XI, 1970.
5. a«8« Aloxandor and A.a«Biitl«r« J«Chtis.Soc*Porkin XI 1976, 696.
6» F« Faigl, Spot taeta in Organic Analysis, El savior, Affistardam, 6th edition, I960.
7. t\ C^roahi snd r.2.ChJrothi,Anal.cham. ,1966,^,19S6.
8. M. Quraehi, f .Z.Quro6hi and S.C.f^inghal,Anal.Chin. Acta, 1971, lia* 361.
9. >¥. Qurashi, f.Z.Qiiroshi,H.!^. Rathoro and A.riOhatRinad, J. Phya. Chan., 1975, 79, 116.
10. K.t. Laidlor* tHoaction Kinotica, Voluma 1, Parganon Pfm, Now York, p. 16., 1963.
11. I.!.. Finar, Organic Chaeii«try, Voluaw 1, English Languago Book Socioty, Fifth Edn. p. 841. 1970.
1?. M.Brookhart, G.r.Lovy and S. wins tain, J.Aawr.Choau Soe. ,1967, SO,, 17351 G.A. Olih, D.H.O*Brion, and M. Calin, ibid. p. 358?.
13. C.F. Walla, t^ana. Faraday Soc., 1967, 6^* W l < '-T.McTiguo and J.M.SiBW, Auatral. J.Choai. ,1967, 2£>90d*
14. N.J. Leonard and J.V. Paukstalis* J.Or^.Chan., 1963, 2SL* 302JU
15. J.K. Oatta (hipt», and N.N. faha. Acta, Crysttllographica, 1973, ?9(6) , 1228.
16. H.S.Rathor« and AtRia Prekash.CunpubllaKad atudlaa).
© * * • »
/\ TEmTIVE AMP fgLgCTXVg .IgSIN r?OT T'-HT FD: Clt^IC ACIp
82
c i t r i c Acld(l) i s ont of tht ioporUnt acids exist
in plants. It occurs In cseny fruitst in btet roots; in
win« • te . It if; also present in ths human and animal
oz^snisffie* c i tr ic acid and ita saltaC?) are usad in tha
menufactura of aoft drinks„ printing of Calico, blua print
papera alto* It i s uaad for forming solubla conplaxas of
cations in ion axchanga in order to raise the analytical
potential(3»4,5). About ten procedures for the colori*
metric detection of c i tr ic acid have been prescribed in
Feigl'a book(6). the tast baaed upon the conversion into
ainneniuM eitraginate by fusion vtl^ urea i s the moat
sensitive and eelective ( l i i s i t of identification 2yug).
However, i t involvea a lengthy procedure i . e . a blank
without urea and exanination of the fluorescing aolution
after addition of Is9 hydrochloric acid are advisable. In
addition to the above a awat sensitive colour tast with
tertiary amines in acetic anhydride (AC^o) haa been
deacribed(7). Unfortunately i t has been studied in a
cursory manner. Recently awthoda depending on fluorescencetS,^
gas- li<»ild chrof»ategraphy{ 10,11), paper chro«atoqraphy(l5>),
83
•niyiMtl^ rtactlorti 13), partition and paptr chromato-
9ra|^y(|4)» i?«v«»a« phaaa paxtlt im thin fys ehxomato*
9raphy( 15) • dansity-gradiant cantrifugationC 16)»
eomplaxo^tryClT), potantioatatic tltrationC 18) and solid*
etata capillary 8pot»taft(l9) hav« bean published.
A siepla, fastt sensltiwi and selactlva tast for
c i tr ic 0<!ld is daacribad in thia cofwunicatiwi. Tha raethod
i« baaad on tha raaetion of raain baad quatamary aroiaoniwa
forraata iproup with citr ic acid in tha prasanca of Ac O.
It hae b#an raportadi that on haating tartiaryemina,
l-phanyWSN-diraathyl-SGiinopropana, with Ac** solution of
citrict ^conitic and ©aIonic acids giva rod, violat or
blua colour «^lla othar aclda do not produca such colour^?).
p»Dir!tathylafsin^anzaldahyda(20) in AC^O glvas oranga colour
with o»hydroxybanzoic, o»hydroxyhippuric and o-hydroxy*
phanyl«>acatic acida^ p*hyd]roxybanzoic» p*hydroxyhippuric
and p«hydroxyphanylacatic aeida> and p-hydroxycinnaBio>4-
9lycina. In aquaoita HCl(2l) i t givae blua colour with
5»hydroxyindolaacatic add, p»PiiRathylaaiinQi>anxaldahyda(?2)
solution in pyridine givaa a rad colour with hippuric acid
in tha praaanca of Ac O and i t ha a baan usad for tha
datarMinati<m of hippuric acid in urina and llvar honoganata.
Howa imr. quatarnary annimiuiii salts instead of tertiary-
aainea or their stlta have net yet baan used for the
84
dtt«ction of eajrboxylie acids* H«sln btads h«v« b««n
U8«d as a reaction ntdia for tha datactton of inorganic(23)
ae ««ll as organic 8ubatancaa(24,^»26). 1^9 uaa of
resin baada raisas tha aanaltivlty and salactlvlty of tha
colour reaction and i t also helps in elucidation of the
reaction ccachanisffi by indicating the charge of the
product. The colour reaction described in thia paper
involves the resin beada aa reaction media and their
quaternary ammoniuia gvoaps aa one of the raectanta. Ihua
the use of the reein beada further increeaea ^ e
selectivity of the reaction.
85
Bf.ft9in^t ayH „„i,t|IJ|tfmil[ll » OOW»K i XS in «i« CV form
was i9iffi«rs«d in fonsie acid (85^) for ^ hr. TH» formic
acid wst r@R!0¥td by decantation, baads wara washad
savarat tiMmt wltli d i s t i l l ed wstar in ordar to remova tha
axcate eeid and driad at rooai taeiparatura{!?5^C), Tha
rssin so obtainad In tha formata form WBB usad for tha
ttat* Ail tha readouts yead tiara of Analytical grada.
Tha followlnf solutions vmtB uead ae raagantsi
(a) {>.Diffiathylaiain(^aniaidahyda ( ^ in ath8nol)*Ac^O in volufsa ratio l i l .
(h) Citric acid (2^ in athanoD-Ac^O in tha voluisa ratio It l ,
(e) Sodiuatformata i^ a< MOiia solution)»ACgO in tha voluiM ratio l i i .
Bauach and t9Wb ^Spactronlc 20* was usad for tha apaetro*
phot«n»tric viovk,
PlMtSltltt « <I) A faw drop® of th« tast aubitanca in
athanol or in diatiliad watar^?»3 dropa of AC2O and ^ 3
raain baade in fortMta fom wara placad in a microtaat
tuba and than i t waa placad in boiling watar for t*3
ninutaa. A positiva raaponaa wae indicatad by tha
86
api»«si?»nc« of a dt«p rttf eolouir dii thv r«sln btadt .
(XZl A f«w <tr«»t»ft #f tH« t«&t «yti6t«fi«# in o^«fiol
or in d i s t l l l t d watoir or • l i t t l « of tho «olid was placad
In a miesot«fit tulKi and ovaporated in a wator bath* Af tar
eoollng* a drop of tha raagant was addad and tha tuba was
placad in boiling mQ^t for S^S mimi1»&« Th@ colour so
davalopad was racordad.
( I l l ) A fow drops of tha taet tubatanee in athanol
or in d ia t i l l ad water and ^ 3 raain baads in Cl* form wara
placed in microtaet ^ b a . Aftar a thorou^ shaking, th%
raagant waa added and tha tuba was placed, in boiling water
for ?»3 fainutas* The colour so developed on the resin
bead® was recorded*
87
a K ^ u h IS
Bdsults obt«in»d by th« ys« of raftg^nt *b* and
proctdur* *II* for the dot«ctl<m of compounds containing
diff«r«nt functlmtsl groypu are aummsriEad in tablaa 1
and 2. aaegant 'a* by procadurt •II» usad for the
dataetion of scidt, Tha x-asulta so obtained are given in
table 3* Fteagant *e* by procedure *II* i s more sensitive
and selective for the detection of acids. The results
obtained ere given in table 4. Heagent 'b* by procedure'III*
can be used for the detection of salts and ecidsC Table 5).
In tho presence of ACAO Oowex l*X3 resin beads in foxmate
fore are used (procedure *X*} f'>r ^ e detection of acids.
The results obtained are recorded in table 6.
88
R B 5 W J
T«blt*i. Detection of y^rioufi Oroan^ r
C^jHwnds which aim oos l t lv* to»t I COiipounds
Ac«ta»id«
Aeridino
3«Alaiilnt
OI.*AlanSn«
Adtnino
Arabin080
Bacfeiturie acid
3ruclnt
I•3»dibutylthiourta
Dia^anolanina
p-D iina thyl amino* banxaldahydo
Din*thylfovmamidt
Oiphanylanina
Qalaetoso
Qlycina
UHiatidina
DL-Mathionina
nicot inic acid
JKN i trobanxa Idahyda
Colour in cold
m Y
Mo
No
Mo
Mo
Wo
No
Mo
Mo
LY
No
No
No
Wo
No
No
No No
Colour f Hot \
Y
9Y
Y
|>Y
tP
OY
LY
^
tY
Y
R
Y
LY
Y
Y
Y
LY LY
oiRDounda mi%}i Raaqant 'l^'
Conpounds which g l v t nagatlva toat
Acatonitrilo
Anilin*
! ( • ) Asoartic acid
Banxaoidt
Oanzidittt
Bansoic acid
Bantonitrilo
Caxbazola
p-Chlorobanzaldahydo
L-Cystina
Oimathylamina
l,3«>Dinitrobanzina
Ethylasssonium chlorida
Fructost
Glucoao
L«Qlutamina
liydrazina hydrochlorida
Indole
taetoaa
m^U r l ' (continutd)
89
^p««p< tfri<|j yfh*<;|i,,qJ^Yf. iff?ffiityf t t i l conpounds Colour
In cold Colour
Hot
Compounds which giv* ntgativo t9ft
poNitroph«nol
t«?h«nyl0lanino
?hdnylurea
Pyridine
Pyrogallol
Pyrrolidine
^arcoclne
Ttilourea
Triethenolamlne
Trimethylamine DL-Tryptophan
t^o
m r;o No
bJo
Mo
Mo
Wo
No
Y
No
va PY
LY
tv LY
OY
LY
Y
Y
BY
LY
Maltose
E^lezitose
5£ethylanmc»)lum chloride
N«{fclethylurea
0< -Naphthy1amine
t^icotinenide
cVNltroaniline
p»N1trobenzaIdehyde
Orcinol
0-Phenylened iene
N-Phenyl-C>»NaphthylaBsine
p*Phenylenediamine
Phloroglucinol
O<*?icollnic acid Pyrrole Rhat&nose falicylanide nalicylaldehyde Succinanide Sucrose Taurine
90
Table •!• (uontlnueii)
Coapeundg which q j v pot l t lw t»«t Coffipounds Colour colour
in cold Hot
CoRtpounde «»hich glvo nogativo t«ft
tbiamint hydrochloridt
DL-0- Tol ly 1 th iou:raa
Tlpon
Tr lew thy I ansson ium hydrochloride
Ur«»
Xyloao
Y » Yellow* B-8rl9ht, PY • Pale Yellow, L»Llght, P^ink,
0«3range, H • led, V • Violet,
91
W^^t,?2» PjLU^%.lm.MLSf^m a^^lt^ nX^ MfmviX ,.!fe*
S»U8 which givt pog i t lv ^ f t , Sal ts Colour Colour In
in cold Hot
r.alts «^ich glvo negttlvo tost
AfastwiluiB forcBdtt
Blsiauith caxbonate
Magnosium carl>m8t»
tJlckel carbonato
Potaeeium ecotato
Potaesiuet carbonate
Potasaiun hydrOMido
Potasslun iodidt
Olaodiun hydrogonphosphata Mo
SodiuBi acatatt
Sodium arsanato
rodiuis bicarbonato
rodluffi broHildo
Sodiun cai^iMiata
Sodiun cltrato
SodiuM flu or id* 5 odiii« femata
SodSuai hydroxido
no ? Alutsiniun eerbonata
tlo Y / unmiuffl acetate
no 0 Ainnoniun cazbonate
^o LY Annoniuffi hydroxide
Mo Y AsRsonlua c h l o r i d e
no Y AsmoniuBi n i t r a t e
Y BY 9ariufB carbonate
m tY c^lciun carbonate
pY Qipric carbonate
no LO Lead a c e t a t e
Nri LY Potaeaiuai bromide
NO Y Potaaalun chloride
No W PotataluB nitrate
No LO Potaaalun aulphate
No Ya Sodlua blsauthata
LY Y Codium b i s u l p h a t e No a SodiuB chloride
LY YR BodluM d l h y d r o g e n orthophoa* phate
92
labl* «» . (cofitinu«d)
r » i f ^ i c h q i v po»itlv» t» i t Salts Colour Colour ****
in eol4 In Hot
falta lAiich givt ntgatlvt
SodiuB flMtavantdstt
^odluti iBolylNdlata
Eodlust nitrita
f odiuQ orlttovanadatt
Sodium sulphata
Sodiun eulphlda
Sodium iulphita
Sodium tartarata
6odiua tutigatata
Sodiun matal
TrieodiuM phoaphata
Doivax 50W.X8 In ti**' fom
Zinc eaztoonata
1 0
KO
No
Ho
t4o
m
no
Ho
Mo
No
NO
NO
No
tY
ny
Y
G
tY
LY
Y
Y
Y
Y
PY
a
Y
rodium nitrata
fodluRi nitropruealda
ftodium oxalata
fodiun sil ieata
Strontlusi acatata
Str<»itiue) earbonata
Abbraviationa aana at in Tabla 1.
93
i f t t
Acids «»hich givf pot l t iv t ^^st Acids
Ascoxfoic
Barbituric
Citric
Ifidolyl»3»ficetlc
Maleie
BaIonic
Phthalie
Colour in cold
Ho
Y
m no no
No
No
Colour in Hot
BY
0
' BR
i.y
Y
LY
pY
Ac ids tvhich givt nogativ* tos t
Acetic
'dipic
Benzoic
Boric
cittnanie
Formic
Pumaric
a a l l i e
Glutanic
Malic
Oxalic
naIicyl ie
Succinic
Tartaric
Uric
Abbreviations saise as in Table 1*
94
» ^ » Tabl« -f. Dtttetlon of ROB* Acldt with aoagtnt e
Acl^ tt^tch glvt p9§ltlv> t»»t Acidt Colour Colour
in cold in Hot
Acids which glvo nagativo
asxblturie
Citric
no No
BY
a
Acatle
Adiplc
Aecoxbic
Bensole
Boric Cinnatsic
FOrsilc
l^nar ic
Gallic
Glutamic
Indolyl»3» ec« tic
ffalalc
Malic
MaIonic
Oxalic
Phthalic
Salicylic
Succinic
Tartaric
Uric
Abbraviationa saao aa In Tabla 1.
95
Tabl» -5 . D«ttction of Hon* Acids and rout oth«r c onpoundt wifA Raagant 'b'
CoBrpounds «rhich ^Iva Coffipounds
Adunoniun acatata AmfDonluia citrate Acaianlum fenaate Formic acid Sodium acatata S<)dlun)i carbonatt Sodium formata
poeltlva taat Colour
In cold
No no Mo t.'O
No m r o
Colour In Hot
LY LY
n ri
Y Y R
roai|»(»jnda «^lch giva nagatSva taat
Acetic acid Adlpic acid /xT'oniun oxalate Ascoxblc acid Qacblturlc acid Qanxole acid 3orlc acid Clnnamlc acid Citric odd Bthyl formate Formaldehyde Fumarie acid Qallic acid Glutamic acid Indole Indolyl*3»acatlc acid Ma laic acid fiallc acid MaIonic acid Oxalic acid Phthalle acid
Reaorclnol Salicylic add Succinic acid Tartaric acid Uric add
Abbreviations wmw at In Table 1.
96
Tabl« «6. Dttaction of tont aclde with dmmit 1»X8 in tht prtetnc* of Ac * .
(>9Mn ^M^h j yf p^g>tivf.,.t«jiii Acids Colour Colour in
in cold Hot
Acidt which givo nogativ* ttat
Barbituric Citric
No ^o
y Acatlc Adipic Ascorbic Bontoic Boric Cinnamic Fonaic Aitsarlc Qelllc Glutaratc In do lyl* 3» aca tie Maleic Malic Malonic Oxalic Phthalie Sal icyl ic ^cc in ie Tartaric Uric
Abbraviationa laaw aa in Tabla 1«
97
In 1955 OhkuBi«(7) rtporttd that ttrtlBryamintt «ih«fi
heattd larith c l tr ie , econltie and malonie acids in fiej) glvt
T9dt violat end biua coimirs r«8p«etiv»ly. Othar caxboxyllc
acids do not product such eolotirs* This is the oost sanaitiva
colour reaction peculiar to 8liphatic»alicyclic» aroosatic*
aliphatic and eressatic tertiaryaminee* Like tartiaryaminea*
alkali and alkaline earth oetal ealta of organic and inorganic
acide also give a positive reaction but other sietal salts
are negative. Aftantrarde in 1966 Feigl(6) etated» ''Tertiary-
arsine aaltSt tertiaryesines, ^aternary amtnfmium ealtst salts
of potassiuffi» ruhidiuBi, caeaiym, strontium and hariuffi and
salta of alkali ami alkaline earth netals with organic acids
behave sinllarly*. The Cheiaistry of the reaction le not
known. Thii reaction can be used for the detection of tertiary
amines. Peigl also gave a l i s t of 31 tertiarynsiines which
can be detected by this colour reaction. In 1970 F , ^ l l and
Averell(27) resiarked," Although the reaction has not been
studied i t appears to be quite specific for tertiaryaminea."
Thua i t ie obvious that the reaction i s full of analytical
potential and can be used for the detection and dettriainatien
of various acida, natal sa l ts , tertiaryanines, tertiaryaaiine
98
$«ltt and quaternary afsnoniun salts* I hava nada a t>)vough
study ragardinf tha analytical u t i l i ty of thla raaetlon.
Tha rasulta obtalnad ara dlacuaaad btlew i
Citric acid in ACgO (proeadura 'II* and raagant 'bM
16 usad for tha dataetioo of nuaaroua organic compounds
c<M)talnlng dlffarant functional groups (labia I)* Tha
rasulta obtained ara in good agraament with thoaa raportad
by Faigl(6)f l .e , i t givaa vary Intansa colour «ritl)
tertlaryasiinas and thair datactlcm can bo oeda succasafully.
The reeulte obtained for the detection of salts
(Table 2) show that potasaiun salts behave ilka sodiun salts
but each salt of potassium and sodlun does not produce
colour. Potasslusi carbonate gives yellow colour e^lle the
carbonates of bariun and strontium do not give any colour.
Sodiun oxalate and potaasiuai acetate do not produce any
colour* A«BM>nlun femate and sodlus foi^ste give very
Intenae pink and red coleiira reapectively* Therefore the
reaction can be uaed for the detection of eodlun and
aanoniusi fonaataa. The l ia i ta of identification for sediuRi
foraate and aaaanluM feraete i s found to be 10 m •nd 132 Aig
respectively.
99
T«blt 3 thowt that th« colour r««ctlon can b« uttd
for th« dotoctioA JUHI tho dotoinninatioA of various organic
acida* Out of twtnty t«fO acids studitd, fiftaon do not
9ivt any colour whila eevan produea diffarant colours*
Aecoztoic, barbituric and ci tr ic acids can bo datactad
eelectivaly*
Tabla 4 shows that l^a usa of sodiun fonaata in tha
pleca of tartiary aminos or tartiaryamina salts nakas
raaction vary sansitiva for tha dataction and datarminati<m
of organic acids* By the pToeadura *I1* and reagant 'c*
only barbituric and c i tr ic acidsproduca colour* The
raaction is vary eansitiva for tha dataction of c i tr ic acid
and i t can ba dletinguiehad from othar acids undar study,
Tha limit of idantification i s found to ba ICO^g.
Tha dataction of various anions (Tabla 3) and cations
(Tabla 2) can ba isada with raagant *b' and procadura * n i '
by taking than in tha ion>axchanga rasin phaaa. I t ia claar
froB tabla 9 that this procadura ia nost sansitiva for
fonsata ions* Tha liaiit of idantification for formic acid
ia found to ba 50 Aig,
Tha usa of ion*axchanga rasin baada as a siadiusi
as iMll as 8 raaetant i s SMda for tha dataction of acida.
100
Hftsults obtalntd by proc«dur« *I* (Tablt 6) show that
only citric acid and barbiturie acid produc* tha colour.
Tha t9xm»x producae rad colour and tha lattar yallovr.
Tharafora thay can ba distingulahad aaally frooi aach othar
and from tha othar acids undar study, tha liiait of
idantificatlon of c i tr ic acid i s found to ba 10^g. Tha
datection of c i tr ic ecid (20/ug) i s ffiada in tha prasanca
of ramainin9 acids (lOOyug) succassfully. This raaction i s
so sansitiva that 9vn diluta vagatablae and fruita Juicaa
can ba tas t^ . tha proeadura was triad with auccasa on
la!Bon» orenga and totsato Juicaa. Tha taet waa mada with
a drop of Julca of fraahly cut surfaca of fruits or
vagatablaa.
Rad raain baads dbtainad in tha abova raacti<m
war* washad aavaral tiraae with tha following solutions^
but tha rad colour could not ba alutadt anmonium
hydroxlda (4N), Bantana* chlorofom» diati l lad watart
athanol» glacial scatic acid, hydrochloric acid (4N},
mathanol, oxalic acid (4N)» parchlorie acid (4N), sodiua
chlorida (4N) and sodiun hydroxlda (4N) aolutlons. Howavar
on traating tha baads with concantratad hydrochloric acid
tha colour diaappaara and af tar washing with dist l l iad wator
10 i
I t reapptare* Hftd coloux d»taintd from th« ]r««ctlon
mixtttrtt «odittra fazoate»cltrle acid • hcj)t was obtorbcd
by DovMx SO'vxS in H* fore and r«d cation axehang* rtsin
beads bahaved like red anion exchanga rasin baada under
the above treatatent* i . e . red colour could not be eluted
frcxB i t . I\enc9 either the red product ia a Z^ittex^ion or
la positively charged apecles that react with anion exchange
reein* The paper chromatography of the red product revealed
that i t reaaine aa a coaqyact single spot correapond to the
R valuea O.CC. 0.90 end C. 8!5 in bensenot ethanol and
dist i l led water respectively. It seems that Itie red product
is a single prese t . The absorption spectrum of i t eho«m
in figure 6 supports the above concluaion beeeuae i t haa a
eingle aiaxiaa at 910 tm* The red compound aeettis to be tlie
following t
RCH • C - CO RCH • C • CO ^ n ( •» 1 >0
C • CO C m C
where R • NaO or >N • ^ y-or Resin quaternary axMoniuai
salt 'O. The fimilar produetTsas been propoaed for hippurie
acid(: ).The further vork to characterise the product ia in
progreaa.
102
AGO 440 460 5?0 560 600 640
Wavelength (nm ) FtG. 6 THE ABSORPTION SPECTRUM OF THE
RED SOLUTION CONTAINING CITRIC ACID ( iml or 2 V,), SODIUM FORMATE ( 1 ml OF 2 %) AND ACETIC ANHYDRIDE ( dmi)
103
L P, {Carr«r, Oz^anlc Chtmittxy, <«vi«T* Anettti-dM) p«290, i938#
2. M,!• Astl«» J.n, fhtltofitOrganic Ch«mletry 7nd •«!., Oxford a BH, ntw Delhi, p. 985 1970.
3« UM* Pergu&ofi, T*xt 3ook of Organie Chtmletry* 2nd •d, D.Van t^ostrand* Princaton. Naw Jarsay* p. 357 1968.
4. M. Qurathl, K«G.Varehnayf a.C. Kaushlki Anal* Chaau , i^y^, 4a 2433.
d. as* Quraehl) H.S, riathora. • a.C.Kauahlkt AnQl. Chain., 1975, 4a, 1710.
6. F.Felgl, Spot Taatt in Organic Analysis, 7 ^ ed-j Clcaviar, Aaatardam 1966.
7. S,DhkuBsa,, J.Fharsi. Soc, Japant 1955, JJi, 1124.
8. J.J. ilyhar., UMarai., A.Kukaia, Analyt. Blocharai 1974, ^ ( 1 ) , 188.
9. H. tan^ , 3. Lang, J, rhromatograi 1972, 7;|, 290.
10. S. HautaU., ^L.w«avar, AnaLBiocham., 1939,30(1), 32.
11. D,S, Zaura., J.Matcoff, ^xnal. Cham., 1969, 4^, 1781
12. J.Fitaleon., J.Ats.'^ff.analyst.Cham. ,1969, a2(33),646.
13. K.Moahlar., S.toosar, Z. Labanamittalyntars u.«>Forcht 1969, 14C{2), 94.
14. tCttoahlar, H.Piras, ibidi 1969, 140(1), 3.
104
15. Q. ''ulllvan., J.E. Alters, J.Phann. f!cl.» 1969, aa(7), 887.
16. A. Mantag., Z, Lebancmltteluntars* u*»Forcht 1973,
17. P.K, JalBmU , K,L,y8dava., Ind, J. Cht»i 1973, JU. 837.
18. J.J. Kankare., Anal. ChwM 1973, 4^, 1877. 19. K.M. Akhtar., H. n, tiathort, M. wurestiit Talanta
{In preae)
20. G.N. GBffnay., K, fchralnr., n. DiF«rrant9»» K.I. Altffisnj J.aiol. ChaiB., i9S4, 706. 695,
21. H.K. B»rry,, H.P,r«ltoni J.S, Barry, Univ» TeK©t Pub. 1951, 22. f^o.9i09.
!>?. «", OhKorl,, K. Ikeda., r.Klra,, 81. Ogstai Anal.Chem., 1977. 4 i , 1494.
23. M,BjJlraotoj CharolsV .nalytj 1960, 4 i , 4.
24. M. Qurashi., r.z.Qurashit Anal.ChlB.Actaf 1966,
!>5. U* «<yrashi| ^.Z.C4ur«thit Anal. Chaai. 1966, ^ , 1996.
26. H.Z.qura«hl| M.S.H8thl Ibid., 1975, 42, 1424.
27. r.A, Strtull and P.R. Avtrall, Tha .Analytical
(hamittry of Nitrogan and Itf compounds, Wilay*
Intartclanet, Naw York Part 1 p. 271, 1970.
