7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 1/46
Chemistry 5
The Art and Science of
Chemical Analysis
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 2/46
Introduction to Chemical
Analysis• Chemical analysis includes any aspect of
the chemical characterization of a sample
material.
• Analytical Chemistry?
– “Science of Chemical Measurements
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 3/46
Areas of Chemical Analysis and
!uestions They Ans"er • !uantitation#
– $o" much of su%stance & is in the sample?
• 'etection# – 'oes the sample contain su%stance &?
• Identification# – (hat is the identity of the su%stance in the sample?
• Separation# – $o" can the species of interest %e separated from the
sample matri) for %etter *uantitation and identification?
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 4/46
(hat do Chemical Analyst 'o?
• Analyst#
• Applies +no"n measurement techni*ues to
"ell defined compositional or
characterization *uestions.
• ,esearch Analytical Chemist
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 5/46
(hat do Chemical Analyst 'o?
• Senior Analyst#
• 'e-elops ne" measurement methods on
e)istin principles to sol-e ne" analysis
pro%lems.
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 6/46
(hat do Chemical Analyst 'o?
• ,esearch Analytical Chemist#
• Creates and /or in-estiates no-el
techni*ues or principles for chemicalmeasurements.
• or
• Conducts fundamental studies ofchemical/physical phenomena underlyinchemical measurements.
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 7/46
(hat is Analytical Science?
• Analytical Chemistry pro-ides the methods andtools needed for insiht into our material "orld0
for ans"erin four %asic *uestions a%out amaterial sample?
• (hat?
• (here?
• $o" much?• (hat arranement1 structure or form?
• 2resenius3 4. Anal. Chem. 6 7899:;#<8:=<8
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 8/46
©Gary Christian, Analytical Chemistry, 6th Ed. (Wiley)
Qualitative analysis is what.
Quantitative analysis is how much.
Qualitative analysis is what.
Quantitative analysis is how much.
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 9/46
Fig. 1.1. Steps in an analysis
An analysis involves several
steps and operations which
depend on
•the particular pro!lem
• your e"pertise
• the apparatus or
e#uipment availa!le.
$he analyst should !e
involved in every step.
An analysis involves several
steps and operations which
depend on
•the particular pro!lem
• your e"pertise
• the apparatus or
e#uipment availa!le.
$he analyst should !e
involved in every step.
©Gary Christian,Analytical Chemistry, 6th
Ed. (Wiley)
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 10/46
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 11/46
%i&&erent methods provide a ran'e o& precision, sensitivity, selectivity,
and speed capa!ilities.
%i&&erent methods provide a ran'e o& precision, sensitivity, selectivity,
and speed capa!ilities.
©Gary Christian, Analytical Chemistry, 6th Ed. (Wiley)
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 12/46
$he sample sie dictates what measurement techni#ues can !e used.$he sample sie dictates what measurement techni#ues can !e used.
©Gary Christian, Analytical Chemistry, 6th Ed. (Wiley)
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 13/46
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 14/46
Trainin of Chemical Analysts
7Analytical Chemists;• Trainin focuses on principles and
techni*ues for sol-in measurement
pro%lems 0 %ut0
• Chemical analysts interface multiple
disciplines to the solution of chemical
measurement pro%lems – >hysical=1 oranic=1 inoranic=1 %io=chem=1
physics1 math1 %ioloy1 electronic1 computers
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 15/46
Chemistry 5
Trainin 2ocuses on• nderlyin principles of chemical
measurements 7 interatin all chemistry
fields1 math1 physics1 %ioloy1 electronics1and computers;.
• 'e-elopin proficiency "ith *uantitati-eanalysis la%oratory procedures
• @)posure to role of chemical analysis in a %road rane of modern science.
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 16/46
Chemical Analysis Affects Many
2ields• >hysical=1 ranic=1 01 Chemistry#
– “Theory uides %ut @)periment decides
• Biotechnoloy# – 'istinuishin isomers "ith differin
%ioacti-ities.
– Biosenors• Materials Science#
– $ih=temperature superconductors
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 17/46
Chemical Analysis Affects Many
2ields• Manufacturin#
– !uality control of pac+aed foods
specifications
• 2orensics#
– Chemical features for criminal e-idence
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 18/46
,ole of Analytical Chemistry in
Modern Science• Case Study 8.
• uclear (aste
'isposal – uclear >o"er >lants
– uclear ,eactors
– (eapons >rocessin
– (eapons 'isposal
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 19/46
Nuclear Waste Disposal Case Study
One Disposal Plan:
seal waste in corrosion-resistant containers
bury 1000’s of feet underground roc!y
strata abo"e water table#
$ust re%ain contained for& '0(000 years
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 20/46
Nuclear Waste Disposal Case Study
• Technical >ro%lems#
• Metal >ac+ae Corrosion#
– M D "ater1 o)yen1 o)idizersM ions D
products
To human
"atersupplynderround
"ater
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 21/46
Nuclear Waste Disposal Case Study
• ,epository a%o-e "ater ta%le1 %ut some "ater
present
• Model e)ists for chemical reactions1 rates1 andtime=dependent dispersion of products and "aste
• >redicted containment time depends on -ery
accurate measurements of microscopic corrosion
processes o-er short periods 7"ee+s1 months;
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 22/46
Nuclear Waste Disposal Case Study
• Corrosion $odel:
• M D $:1 S6:=1 : MD D $= 1 $:
• CE1 $D1 2=1 Cl=1 M&nD #
• :=1
=1 SE1etc.MFmD1 MGH D >rod.
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 23/46
Nuclear Waste Disposal Case Study
• (hat 'o (e eed To no"?
• Ja%oratory Simulation Studies
• (ater Composition at site %efore container placement.
• (ater Composition after e)posure to container
– )i%e dependence rate of product growt* o"erwee!s+%ont*s#
– S%all c*anges %ust be %easured "ery precisely
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 24/46
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 25/46
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 26/46
uclear (aste 'isposal Case Study
Analytical Chemistry Issues#• (hat species to %e measured?
• (hat precision is re*uired?
• (hat measurement techni*ue?
• (hat are the sources of error?
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 27/46
uclear (aste 'isposal Case Study
Analytical Chemistry Issues#• @)ample# C
E Analysis
• Species? CE1 $C
=1 $:C ?
• >recision?D/= 7 K.8L1 K.K8L1 8KL;• Techni*ue?
– D/= 8=:L Ion Chromatoraphy
– D/= K.8L Acid=Base Titration
• @rror Sources? – Acid=Base 7ther Bases Interfer;
– Ion Chromatoraphy 7p$ – 'ependent ,esults;
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 28/46
uclear (aste 'isposal Case Study
Analytical Chemistry Issues#• (hat Car%onate Species?
• CE D $: $C
= D $=
• $C= D $: $:C D $=
• $:C C:7; D $:
• Temperature1 >ressure 'ependence
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 29/46
uclear (aste 'isposal Case Study
Analytical Chemistry Issues#• If eed C
EN only
– Specify p$1 Temperature1 >ressure
– se Techni*ue Selecti-e for CE
• 7Ion Chromatoraphy;
• If eed Σ [CEND $C
=N D $:CN
– ,emo-e Interferences
– Acid=Base Titration
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 30/46
uclear (aste 'isposal Case Study
Analytical Chemistry Issues# (hat car%onate species is present as a
function of p$?
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 31/46
uclear (aste 'isposal Case Study
Analytical Chemistry Issues# 7Cont.;• ther Chemical Measurements#
• Chromium# Cr :D1Cr D1 Cr :OE1 Cr6
E1 etc.
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 32/46
uclear (aste 'isposal Case Study
Analytical Chemistry Issues# 7Cont.;• (hat does the Analytical Chemist need to
+no" to sol-e these pro%lems?
• Measurement Techni*ues A-aila%le – Titrations1 ptical Spectroscopy1
ChromatoraphyP etc.
• Strenths/(ea+nesses of Techni*ues – Accuracy1 >recision1 Interferences1 ,ane1
'etection Jimits1 etc.
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 33/46
uclear (aste 'isposal Case Study
Analytical Chemistry Issues# 7Cont.;• nderlyin Chemistry/>hysics of the
Sample Material
– Solution Chemistry 7Acid/Base;
– Solids $omoeneity1 Structure
• @rror Analysis
– Sources
– Solutions
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 34/46
'eer ill
• Case Study Q :# 'eer ill
• >ro%lem# 'ead "hitetail deer near pond in
the Jand Bet"een the Ja+es State >ar+ insouth central entuc+y.
• Chemist state -eterinary dianostic
la%oratory helped find the cause
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 35/46
Site In-estiation
• Careful -isual o%ser-ation of a t"o acre
area around the site#
• %ser-ation# rass around near%y po"er= poles "as "ilted and discolored.
• Speculation# $er%icide used on rass.
• Inredient# Arsenic in a -ariety of forms
– C$As7$;: -ery solu%le in "ater.
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 36/46
Select Method
• Association of fficial Analytical Chemists
7AAC;
• 'istillation of arsenic as arsine "hich isthen determined %y colorimetric
measurements.
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 37/46
,epresentati-e Sample
• 'issect %oth deer. ,emo-ed +idneys for
analysis.
• Ja%oratory Sample. >reparation
• Cut +idney into pieces and %lend in a hih
speed %lender to homoenize the sample.
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 38/46
'efinin ,eplicate Samples
• Three 8K= samples of the homoenized
tissue "ere placed in porcelain curci%les
and dry ashed. 'ry ashin ser-es to freethe analyte from oranic material and
con-ert the arsenic present to As:5.
Samples of the discolored rass "eretreated in a similar manner.
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 39/46
'issol-in the Samples
• The dry solid in each of the sample
cruci%les "as dissol-ed in dilute $Cl1
"hich con-erted the As:5 to solu%le$As6.
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 40/46
@liminatin Interferences
• ,eactions to @liminate Interferences#• $5As6 D SnCl: D :$Cl ==R $5As5 D SnCl: D $:
• $5As5 D Gn D $Cl ==R As$57.; D GnCl: D $:• Bu%%le as into collectors "ith sil-er
diethyldithiocar%amate to form a colored comple)
compound sho"n %elo".
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 41/46
Measurin the Amount of
Analyte• Spectrophotometer# $ihly colored
comple) of arsenic "as found to a%sor%
liht at a "a-elenth of 55 nm.
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 42/46
A!sor!ance vs Concentration
y = 0.0282x + 0.005
R2 = 0.9961
0
0.2
0.4
0.6
0.8
0 5 10 15 20 25 30
Conc., ppm
A ! s o r ! a
n c e
Conc. Absorbanc
ppm
0 0
5 0.16
10 0.28
15 0.41
20 0.595
25 0.7
deer 1 0.61
deer 2 0.43
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 43/46
Calculatin the Concentration
• ppm E 7A%sor%ance =.KK5;/K.K:<:
• 'eer 8# 7K.8 = K.KK5;/K.K:<: E :: ppm
• 'eer :# 7K.6 =K.KK5;/K.K:<: E 85 ppm
• Arsenic in the +idney tissue of animals is
to)ic at le-els a%o-e a%out 8K ppm.
• rass Samples sho"ed a%out KK ppm
arsenic.
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 44/46
,elia%ility of the 'ata
• The data from these e)periments could %e
analyzed usin the statistical methods "e
"ill descri%e in Section .
W* D W , i
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 45/46
W*ere Do We ,egin• ,e-ie" of Basic Tools and perations of Analytical
Chemistry
– The Ja%oratory ote%oo+ – Analytical Balances1 Uolumetric lass"are
– Ja%oratory Safety
• @rror Analysis
– Concepts
– Terminoloy
– @-aluation of 'ata
– @)perimental 'esin
• ,e-ie" of Solution Chemistry – nits
– Concentration Calculations
– Stoichiometry
– Balanced Chemical ,eactions
a!oratory sa&ety is a must*
7/21/2019 Section 01 Introduction
http://slidepdf.com/reader/full/section-01-introduction 46/46
a!oratory sa&ety is a must*
earn the rules.
+ee Appendi" %.
a!oratory sa&ety is a must*
earn the rules.
+ee Appendi" %.