TITLE Determination of Total Cyanide by Semi- Automated ... 002 Cyanide.pdf · 5.1 Total cyanide is...

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TITLE: Determination of Total Cyanide by Semi- Automated Colorimetry

REVISION: C

PROCEDURE: SOP DW 002 EFFECTIVE DATE: September 19, 2016

1.0 INDENTIFICATION

1.1 EPA 335.4 – Determination of Total Cyanide by Semi-Automated Colorimetry

2.0 APLICATION MATRIX

2.1 This method covers the determination of cyanide in drinking water.

3.0 DETECTION LIMIT

3.1 Refer to Laboratory Method Quality Performance Data File

4.0 SCOPE AND APPLICATION

4.1 This method covers the determination of cyanide in drinking water.

4.2 The applicable concentration range is 0.005 to 0.500 mg CN- / L.

5.0 SUMMARY OF TEST METHOD

5.1 Total cyanide is determined by distilling the sample and measuring cyanide

generated using a technique for cyanide ion detection (e.g., colorimetry).

5.2 In micro distillation, the hydrocyanic acid is released from cyanide complexes by

means of a manual reflux-distillation operation and absorbed in a scrubber

containing sodium hydroxide solution. The cyanogen ion in the absorbing solution

is converted to cyanogen chloride by reactions with chloramine-T, which

subsequently reacts with pyridine and barbituric acid to give a red-colored complex.

6.0 DEFINITION

6.1 Calibration Blank (CB) — A volume of reagent water fortified with the same matrix

as the calibration standards but without the analyte.

6.2 Calibration Standard (CAL) — A solution prepared from the primary dilution

standard solution or stock standard solutions. The calibration standard solution

solutions are used to calibrate the instrument response with respect to analyte

concentration.

6.3 Initial Demonstration of Capability – Include a reagent blank and four laboratory

fortified blank (LFB) is used to demonstrate proficiency in performing method and

obtaining acceptable results for each analyte.

6.4 Instrument Performance Check Solution (ICP) — A solution of one or more

methods analytes, or other test substances used to evaluate the performance of the

instrument system with respect to a defined set of criteria.

6.5 Laboratory Fortified Blank (LFB) — An aliquot of reagent water or other blank

matrices to which known quantities of the method analytes are added in the

laboratory. The LFB is analyzed exactly like a sample, and its purpose is to

determine whether the methodology is in control, and whether the laboratory is

capable of making accurate and precise measurements.

6.6 Laboratory Reagent Blank (LRB) — An aliquot of reagent water or other blank

matrices that are treated exactly as a sample including exposure to all glassware,

equipment, solvents, reagents, that are used with other samples. The LRB is used

to determine if method analytes or other interferences are present in the laboratory

environment, the reagents, or the apparatus.





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6.7 Matrix spike (MS) and matrix spike duplicate (MSD) - Aliquots of an

environmental sample to which known quantities of the analytes are added in the

laboratory. The MS and MSD are prepared and/or analyzed exactly like a field

sample. Their purpose is to quantify any additional bias and imprecision caused by

the sample matrix. The background concentrations of the analytes in the sample

matrix must be determine in a separate aliquot and the measured values in the MS

and MSD corrected for background concentrations.

6.8 Quality Control Sample (QCS) — A solution of method analytes of known

concentrations that is used to fortify an aliquot of LRB or sample matrix. The QCS

is obtained from a source external to the laboratory and different from the source

of calibration standards. It is used to check laboratory performance with externally

prepared test materials.

6.9 Linear Calibration Range (LCR) — The concentration range over which the

instrument response is linear.

6.10 Method Blank - An analyte-free sample to which all reagents are added in the same

volumes or proportions as used in sample processing. The method blank must be

carried through the complete sample preparation and analytical procedure. The

method blank is used to assess contamination resulting from the analytical process.

6.11 Method Detection Limit – The minimum concentration of an analyte that can be

identified measured and reported with 99% confidence that analyte concentration

is greater than zero.

6.12 Minimum Reporting Limit (MRL) – Is the lowest standard concentration that could

be analyzed obtaining a response using the established analyte’s calibration curve

and could be statistically treated.

6.13 Ongoing Precision and Recovery Standard (OPR) – The ongoing precision and

recovery standard test is used to ensure the laboratory meets the performance

criteria during the period that the samples are analyzed. The OPR solution is an

aliquot of method blank to witch known quantities of the methods analytes are add

in the laboratory. The OPR is analyzed in the same manner as samples.

7.0 INTERFERENCES

7.1 Aldehydes, nitrate-nitrite, oxidizing agents, such as chlorine, thiocyanate,

thiosulfate and sulfide. Some of these interferences are reduced or eliminated by

the distillation process.

7.2 Sulfides adversely affect the procedure by producing hydrogen sulfide during

distillation. If a drop of the sample on lead acetate test paper indicates the presence

of sulfide, treat 25 mL more of the sample volume required for the cyanide

determination with powdered cadmium carbonate. It forms a precipitate if the

sample contains sulfide. Repeat this operation until a drop of the treated sample

solution does not darken the lead acetate test paper. Filter the solution through a

dry filter paper into a dry beaker, and from the filtrate, measure the sample to be

used for analysis. Avoid a large excess of cadmium and a long contact time in order

to minimize a loss by complexation or occlusion of cyanide on the precipitated

material.

7.3 High results may be obtained for samples that contain nitrate and/or nitrite. During

the distillation, nitrate and nitrite will form nitrous acid water that will react with





REVISION: C


some organic compounds to form oximes. The oximes will decompose under test

conditions to generate HCN. The interference of nitrate and nitrite is eliminated by

pretreatment with sulfamic acid.

7.4 Oxidizing agents, such as chlorine, decompose most of the cyanides. Test a drop

sample with potassium iodide-starch paper (KI-starch paper) moistened in acetate

buffer pH 4.0 at time of collection; a blue color indicates the need for treatment.

Add ascorbic acid, a few crystals at a time, until a drop of sample produces no color

on the indicator paper; then add an additional 0.06 g of ascorbic acid for each liter

of sample volume. Sodium arsenite has also been employed to remove oxidizing

agents. Add a small amount of sodium arsenite solution, until a drop of sample

produces no color on the indicator paper.

7.5 Method interferences may be caused by contaminants in the reagent water,

reagents, glassware, and other sample processing apparatus that bias analyte

response.

8.0 SAFETY

8.1 Each chemical should be regarded as a potential health hazard and exposure should

be as low as reasonably achievable.

8.2 A reference file of all reagent’s Safety Data Sheets (SDS) should be available to all

personnel involved in the chemical analysis.

8.3 The following chemicals have the potential to be highly toxic or hazardous:

8.3.1 Potassium Cyanide – Very hazardous in cases of skin and eyes contact

(irritant), of ingestion and inhalation. Severe over exposure can produce

lung damage, choking, unconsciousness or death.

Recommended personal protection:

8.3.1.1 Safety glasses or goggles.

8.3.1.2 Use an approved/certified respirator or manage under certified

fume hood.

8.3.1.3 Chemical resistant gloves.

8.3.1.4 Protective clothing

8.3.2 Hydrochloric acid - Very hazardous in case of skin contact (Corrosive).


8.3.2.1 Face Shield

8.3.2.2 Respirator with vapor protection filter (If not managed under

certified fume hood)

8.3.2.3 Strong Acids and Chemicals resistant gloves


8.3.3 Pyridine - OSHA regulated air exposure (<250 ppm exposure)


8.3.3.1 Full face respirator with Organic vapor filter (If not managed

under certified fume hood)

8.3.3.2 Protective gloves


8.3.4 Sulfuric Acid - Extremely corrosive, causes severe burns with contact and

if inhaled, mist can cause irritation






REVISION: C


8.3.4.1 Face shield and goggles


8.3.4.3 Chemical resistant gloves (Strong acid resistant gloves)

8.3.4.4 Respirator with vapor/fumes/dust protection filters for

environments exposure up to 10mg/m3 (If not managed under

certified fume hood.

9.0 EQUIPMENT

9.1 Analytical Balance, capable of accurately weighing to the nearest 0.0001 g

9.2 Glassware Class A

9.3 Distillation apparatus – Macro distillation (Section 23.5) or Micro distillation

System (Section 23.3 & 23.4)

9.4 Heating block

9.5 Automated continuous flow analyzer- LACHAT Quickchem 8500

SN:070400000435

9.5.1 Sampling device (Sampler)

9.5.2 Multichannel pump

9.5.3 Reaction unit or manifold

9.5.4 Colorimetric detector

9.5.5 Data recording device

9.6 Buret

9.7 Filter Paper

9.8 Lead Acetate Test Paper

9.9 Potassium Iodide –Starch Paper

9.10 pH Meter

10.0 REAGENTS & STANDARD

10.1 Reagents

10.1.1 Cadmium Carbonate Powder, CdCO3(CARN: 513-78-0)

10.1.2 Reagent Water: Deionized Water

10.1.3 Sodium Arsenite Solution (5.0 g/L) (CASRN-7784-46-5) (Commercially

available)

10.1.4 Lead Carbonate Powdered, PbCO3

10.1.5 Distillation Reagents

10.1.5.1 Boiling Chips Environmental Express # C5249 or Equivalent

10.1.5.2 Magnesium Chloride (CASRN-7786-30-3) (MgCl2•6H2O)

10.1.5.3 Sodium Hydroxide (CASRN-1310-73-2), NaOH

10.1.5.4 Sulfamic Acid (CASRN-5329-14-6)

10.1.5.5 Sulfuric Acid (CASRN-7664-93-9) (H2SO4)

10.1.6 Standardization Reagents

10.1.6.1 Acetone

10.1.6.2 P-Dimethylaminobenzalrodanine

10.1.6.3 Silver Nitrate (CASRN-7761-88-8), AgNO3

10.1.7 Instrument Reagents

10.1.7.1 Ascorbic acid: Crystal (CASRN-50-81-7)

10.1.7.2 Barbituric Acid (CASRN-67-52-7)





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10.1.7.3 Chloramine-T (CASRN-127-65-1)

10.1.7.4 Hydrochloric Acid (CASRN-7647-01-0) (HCl)

10.1.7.5 Pyridine (CASRN-110-86-1)

10.1.7.6 Sodium dihydrogenphosphate (CASRN-10049-21-5)

(NaH2PO4•H2O)

10.1.8 Stock Standard Reagents

10.1.8.1 Potassium Cyanide (CASRN-151-50-8) (KCN)

10.1.8.2 Potassium Hydroxide (CASRN-1310-58-3) (KOH)

10.2 Distillation Solutions

10.2.1 Sodium Hydroxide Solution 1.00 N

10.2.1.1 Dissolve 40g of NaOH in reagent water

10.2.1.2 Mix with magnetic stirrer until dissolve.

10.2.1.3 Cool solution

10.2.1.4 Dilute solution to 1L using volumetric flask

10.2.2 Sodium Hydroxide Solution 1.25 N

10.2.2.1 Dissolve 50g of NaOH in reagent water



10.2.2.4 Dilute solution to 1L using volumetric flask

10.2.3 Sodium Hydroxide Solution 0.25N

10.2.3.1 Dilute 200 mL of 1.25N Sodium Hydroxide Solution (Section

10.2.2) to 1L with reagent water.

10.2.4 Sulfuric Acid, 18N (1+1)

10.2.4.1 Place a 1L glass beaker in an ice bath with magnetic stirrer.

10.2.4.2 Add 500 mL reagent water.

10.2.4.3 Add slowly 500 mL of concentrated Sulfuric Acid.


10.2.4.5 Dilute to 1L with reagent water.

10.2.5 Magnesium Chloride

10.2.5.1 Dissolve 510g of Magnesium Chloride with reagent water in 1L

volumetric flask


10.2.5.3 Dilute to the mark with reagent water, invert to mix

10.2.6 Sulfamic Acid

10.2.6.1 Dissolve 20g of reagent grade sulfamic acid in reagent water.


10.2.6.3 Dilute to 1L volumetric flask with reagent water.

10.3 Instrument Solutions

10.3.1 Pyridine Burbuturic Acid Reagent

10.3.1.1 Weight 15g of Barbituric Acid in a 1L volumetric flask.

10.3.1.2 Wash the side of the beakers with about 100mL of reagent water.

10.3.1.3 Mix with magnetic stirrer.

10.3.1.4 Add 75mL of pyridine.

10.3.1.5 Add 15 mL of HCl and mix.

10.3.1.6 Dilute to 900mL with reagent water and mix until the barbituric

acid had dissolved.





REVISION: C


10.3.1.7 Dilute to the mark with reagent water.

10.3.2 Sodium Dihydrogenphosphate Buffer

10.3.2.1 Dissolve 138g NaH2PO4·H2O with reagent water in 1000mL

volumetric flask



10.3.3 Chloramine-T

10.3.3.1 Dissolve 2.0 g chloramine-T with reagent water in 500 mL

volumetric flask.


10.3.3.3 Dilute to mark with reagent water.

10.4 Standardization Reagents

10.4.1 Indicator Solution

10.4.1.1 Dissolve 20mg p-dimethylaminobenzalrhodaine in 100mL

acetone.

10.4.2 Standard Silver Nitrate Solution, 0.0192 N

10.4.2.1 Prepare by crushing approximately 5g AgNO3 crystals and

drying to constant weight at 40ºC.

10.4.2.2 Weight out 3.2647g of dried AgNO3.

10.4.2.3 Dissolve with reagent water in 1000mL volumetric flask.


10.4.3 Sodium Hydroxide Dilution Solution

10.4.3.1 Dissolve 1.6g NaOH in 1000mL volumetric flask.



10.5 Stock & Working Standard Solutions

10.5.1 Cyanide Stock Standard Solution 1000mg/L

10.5.1.1 Dissolve 2.51g Potassium Cyanide (KCN) and 2.0g Potassium

Hydroxide (KOH) with reagent water in 1000mL volumetric

flask.

10.5.1.2 Mix with magnetic stirrer


10.5.2 Cyanide Intermediate Standard Solution 100mg/L

10.5.2.1 Transfer 10.0mL of Cyanide Stock Standard Solution 1000mg/L

(Section 10.5.1) to 100mL volumetric flask.

10.5.2.2 Dilute to volume with Reagent Water and mix well.

10.5.3 Cyanide Working Standard Solution 10.0mg/L

10.5.3.1 Transfer 20.0mL of Cyanide Stock Standard Solution 100mg/L

(Section 10.5.2) to 200mL volumetric flask.

10.5.3.2 Dilute to volume with Reagent Water and mix well.

10.5.3.3

10.6 Calibration Curve

Note: Is not imperative that all standards to be distilled in the same manner as the

sample. At least two standards (a high and low) and a blank should be distilled and

compared to similar value on the standard curve to insure that the distillation

technique is reliable. Before distillation, standards should contain 4mL NaOH





REVISION: C


0.25N (Section 10.2.2) per 50.0mL. Theses distilled standard must agree within

±10% of the undistilled standards.

10.6.1 Calibration Curve Standard 0.300 mg/L

10.6.1.1 From Cyanide Working Standard Solution 10.0mg/L (Section

10.5.3) transfer 3.0mL to 100 mL volumetric flask.

10.6.1.2 Add 20mL NaOH 1.25N (Section 10.2.2)

10.6.1.3 Dilute to volume with Reagent Water.















10.6.4.3 Dilute to volume with Reagent Water











10.7 Standards & Quality Control Solutions Preparation

10.7.1 Calibration Blank

10.7.1.1 Add reagent water in 100mL volumetric flask



10.7.2 Quality Control Sample (QCS) 0.05mg/L

10.7.2.1 From Cyanide Working Standard Solution 10.0mg/L using a

different source preparation transfer 0.50 mL to 100 mL

volumetric flask.



10.7.3 Instrument Performance Check (IPC) 0.03mg/L







REVISION: C




10.7.4 Laboratory Reagent Blank (LRB) & Laboratory Reagent Blank

Duplicate

10.7.4.1 Add reagent water in 100mL volumetric flask



10.7.5 Laboratory Fortified Blank (LFB) & Laboratory Fortified Blank

Duplicate 0.03mg/L





10.7.6 On-going Precision & Recovery 0.05mg/L





10.7.7 Sample spikes (Laboratory fortified matrix):

10.7.7.1 Spikes concentration should be the same as used in the

laboratory fortified blank. Perform sample spikes a minimum of

10% of the total of samples to be analyzed by this method.

Spikes are to be prepared in duplicate.

11.0 SAMPLE COLLECTION, PRESERVATION SHIPMENT AND STORAGE

11.1 Use plastic or glass bottles.

11.2 Preserve with ascorbic acid and sodium hydroxide (pH>12) and cool to ≤4 ºC at

the time of collection.

11.3 Samples should be analyzed as soon as possible after collection sample should be

checked for possible interferences. If storage is required, preserved samples are

maintained at ≤4 ºC and may be held for up to 14 days.

12.0 QUALITY CONTROL

12.1 The laboratory must have records of the implementation of proper quality controls

to ensure the validity of the results that the client receives after this technique is

applied. This must contain evidence of the following being performed and verified

periodically (if applicable):

12.1.1 Linear Calibration Range (LCR)

12.1.1.1 Must be determined initially and verified every six month. The

initial demonstration of linearity must use sufficient standards to

insure that the resulting curve is linear.

12.1.1.2 The verification of linearity must use a minimum of a blank and

three standards.

12.1.1.3 Is determined by successive analyses of higher concentration

standards until the results are less than 90% of the target value

of the standard.





REVISION: C


12.1.2 Initial Demonstration of Capability (IDC)

12.1.2.1 Must be determined when every new analyst performs this

analysis to demonstrate proficiency with the analytical method.

The analyst must recalculate IDC when a change in the method,

analyst or instrument is made, after prolonged shutdowns, mayor

instrumental repairs and whenever a change could affect the

precision, accuracy or sensitivity.

12.1.2.2 Run a reagent blank and four laboratory fortified blank at the

concentration between 10 times the MDL and the midpoint of

the calibration curve. Then calculate the percent of recovery of

each standard.

12.1.2.3 The percent recovery should within 90-110% of it true value,

and the calculated percent relative standard deviation should be

at or below 15%.

12.1.3 Method Detection Limit (MDL) should be determined every six month by

an experience analyst, when a new analyte begins to work with the method

or whenever there is a significant change in the background instrument

response. Refer to procedure ALQAP DW 009- Determination of Method

Detection Limit and Initial Demonstration of Performance to determine the

method detection limit value.

12.2 Laboratory Performance

12.2.1 Laboratory Reagent Blank (LRB) must be analyzed at least once with

duplicate with each batch of samples. Result must not exceed the laboratory

establish MDL value.

12.2.2 Laboratory Fortified Blank (LFB)

12.2.2.1 Must be analyze at least once with duplicate with each batch of

samples.

12.2.2.2 Laboratory will establish control limit of data generated from

laboratory fortified blanks using as minimum 20 to 30 analyses

results when data becomes available.

12.2.2.3 Until laboratory establish acceptable control limit, calculate

accuracy as percent of recovery and it results must be within 90-

110%.

12.2.3 Instrument Performance Check Solution (IPC is a mid-range check

standard) must be analyze following daily calibration, after every tenth

sample and at the end of the sample run. Analysis of the IPC solution and

calibration immediately following calibration and the subsequent analyses

of the IPC solution must be verify that the instrument is within 90 – 110%

of its true value.

12.2.4 Laboratory Fortified Sample Matrix (LFM) must be performed in duplicate

on 10% of samples to be analyzed with every batch of sample. The analyte

concentration must be high enough to be detected above the original sample.

The added analyte concentration should be the same as that used in the

laboratory fortified blank.

12.2.5 Minimum Reporting Limit (MRL) must be verify in every batch of sample

by analyzing fortified blank at the minimum reporting limit. The reporting





REVISION: C


limit must be below the minimum contamination level. Percent of

recovery must be within 90-110%.

12.2.6 Quality Control Sample (QCS) is obtained from a source external to the

laboratory and different from the source of calibration standards. Calculate

accuracy as percent of recovery, results must be within 90-110%.

12.2.7 For applicability and acceptance criteria refer to Section 23.2.

13.0 CALIBRATION & STANDARDIZATION

13.1 Prepare a series of six standards (Section 10.6), covering the desired range, and a

blank.

13.2 Pump all reagents and let the system equilibrate until a stable baseline is achieved.

13.3 For additional parameters refer to Section 23.2.

13.4 Place appropriate standards in the sampler in order of decreasing concentration

(Section 23.1).

13.5 Calibrate the instrument with the calibration curve standards and a calibration blank

(Section 23.1)

13.6 Run the standard preparation check or working laboratory fortified blank (Section

23.1).

13.7 Run analysis assuring suitability parameters in Section 23.2 are met.

13.8 Prepare standard curve by plotting instrument response against concentration

values.

13.9 A calibration curve may be fitted to the response data using computer based

regression curve fitting techniques.

13.10 Calculate the concentration of each calibration point. The percent of recovery of

each standard should be within 90 to 110% of it true value. If the difference between

the measure values of the calibration solution exceed ±10% the true value

concentration, the analysis should be terminated and the instrument recalibrated.

14.0 ROCEDURE

14.1 Standardization of Cyanide Stock Standard Solution 1000 mg/L (Section

10.4.2)

14.1.1 Transfer 20 mL of Cyanide Stock Standard Solution 1000 mg/L (Section

10.5.1) to a beaker.

14.1.2 Dilute to 100 mL with Sodium Hydroxide dilution solution (Section 10.4.3).

14.1.3 Add 0.5 mL Indicator Solution (Section 10.4.1)

14.1.4 Titrate with standard AgNO3 (10.4.2) titrate to the first change in color from

canary yellow to a salmon hue.

14.1.5 Record volume of titrant used.

14.1.6 Titrate a blank, NaOH dilution solution.

14.1.7 Record volume of titrate used.

14.1.8 Calculate mg CN-/L of Cyanide Stock Standard Solution (Section 15.5)

14.2 Microdistillation Procedure

14.2.1 Transfer 50mL of sample or standard into the MicroBlock Reaction Flask

(Section 23.4).

14.2.2 Set distillation system. Refer to the schematic in Section for the appropriate

placement positions and flexible tubing connections to cool the Cold Finger





REVISION: C


with running tap water. All air/vacuum valve are in OFF position.(Section

23.3)

14.2.3 Add a pinch of boiling chips. For solid sample weigh 1.0g or less to the

nearest 0.01g, dilute to 50.0mL and add boiling chip.

14.2.4 Pipette 50.0mL of 0.25N NaOH into the absorption Flask (Section 23.4).

14.2.5 Position the Cold Finger and Absorber Impingers.

14.2.6 Turn tap water ON after assuring all tubing connections are firmly placed.

A water flow rate of 50 to 60 gallons per hour is required.

14.2.7 Turn ON the vacuum and slowly adjust each valve to provide an air flow to

maintain a bubble rate of about several bubbles per second for each position

as viewed in the absorption vessel.

14.2.8 Add 5mL of sulfamic acid reagent solution (Section 10.2.5) to eliminate

Nitrite & Nitrate interference.

14.2.9 Slowly add 5mL sulfuric acid 18N (Section 10.2.3) through the reagent

inlet. Allow the air flow to mix the contents of the flask for several minutes.

14.2.10 Add 2.0mL of magnesium chloride (Section 10.2.4) reagent and wash

down with a stream of water through the reagent inlet.

14.2.11 If excess foaming occurs, add an additional 2.0mL magnesium chloride.

14.2.12 Allow a few minutes to mix.

14.2.13 Turn the heat ON and set the temperature of the heating block to 150˚C.

14.2.14 Wait until the system reach the mentioned temperature, then turn off the

heater block in an hour.

14.2.15 Let the boiling flask cool.

14.2.16 Turn air/vacuum valves to the OFF position.

14.2.17 Disconnect the Distillation Head and Absorption Impinger by separating

the Slip Connector.

14.2.18 Repeat steps 14.1.18 to for each sample position.

14.2.19 Allow the tap water to continue circulating through the Cold Fingers which

will allow the heater block more rapidly stabilize in preparation for the

next run.

14.2.20 The distilled cyanide in the 0.25N NaOH is now ready to be analyses.

14.3 Macro Distillation Procedure 14.3.1 Add 500 mL sample, containing not more than 10mg CN-/L (diluted if

necessary with reagent water) to the boiling flask.

14.3.2 Add 10 mL Sodium Hydroxide 1N (10.2.1) to gas scrubber and dilute with

reagent water to obtain an adequate liquid depth in the absorber. Do not use

more than 225 mL total volume of absorber solution.

14.3.3 When sulfide generation from the distilling flask is anticipated add 50 or

more mg powdered lead carbonate (PbCO3) to the absorber solution to

precipitate sulfide.

14.3.4 Connect the train, consisting of boiling flask air inlet, flask, condenser, gas

washer, suction flask trap, and aspirator. Adjust suction so that least 1 air

bubble/s enters the boiling flask. This air rate will carry HCN gas from flask

to absorber and usually will prevent a reverse flow to HCN through the air

inlet. If this air rate does not prevent sample backup in the delivery tube,





REVISION: C


increase air flow rate to 2 air bubbles. Observe air purge rate in the absorber

where the liquid level should be raised not more than 6.5 to 10 mm.

Maintain air flow throughout the reaction.

14.3.5 Add 2 g sulfamic acid through the air inlet tube and wash down with reagent

water.

14.3.6 Add 50 mL Sulfuric Acid 1+1 (10.2.4) through the air inlet tube. Rinse tube

with reagent water and let air mix flask content for 3 min.

14.3.7 Add 20 mL Magnesium Chloride reagent through air inlet and wash down

with stream of water. Precipitate that may form redisolves on heating.

14.3.8 Heat with rapid boiling, but not flood condenser inlet or permit vapor to rise

more than halfway into condenser. Adequate refluxing is indicated by a

reflux rate of 40 to 50 drops/min from the condenser lip.

14.3.9 Reflux for at least 1 hour. Discontinue heating but continue air flow for

15min.

14.3.10Cool and quantitatively transfer absorption solution to 250 mL volumetric

flask. Rinse absorber and its connecting tubing sparingly with reagent water

and add to flask.

14.3.11Dilute to volume with reagent water and mix thoroughly.

Note: When following the macro distillation procedure, the cyanide ion

present in the original sample is concentrated by a factor of two from

distillation procedure. The initial sample volume is 500mL; however, the

cyanide which has distilled over into 0.25M NaOH absorbing solution is

only diluted to a 250mL final volume. Because the nondistilled standards

are not carried through the distillation procedure, they are not

concentrated by factor or two. To compensate for this factor, the standard

concentration are doubled.

14.4 Colorimeter Analysis by Automated Continuous Flow Analyzer 14.4.1 Place the Cyanide manifold (Section 23.6 & Section 23.7) on channel 1 of

the instrument. If this channel isn’t working properly the channel 2 can be

used but make sure to turn on the channel in the software. Verify that the

run sequence is the same one as Section 23.1 and verify the condition of the

instrument.

14.4.2 Turn on the LACHAT (the switch is placed in the right side of the

equipment)

14.4.3 Go to the icon Omnion

14.4.4 Open Alchem methods search Cyanide year month

open a run worksheet.

14.4.5 As soon the worksheet appear a window will be shown asking “Do you want

to change the set points of the relevant heater?” Select YES

14.4.6 Line/Pump Startup

14.4.6.1 Go to configuration instrument pumps

normal function close

14.4.6.2 Pull line to ends of cartridge to ensure proper tension on the line.

Clamp the cartridge to the pump. Clamp pump cartridge down





REVISION: C


only when pump on and rolling. Snap cartridge in one end and

then the other.

14.4.6.3 Set tension on line by clicking the tabs on top of the cartridge

back on click.

14.4.6.4 Keep pump speed on 35.

14.4.6.5 Tubes can pop off the cartridge. If that occurs slow the pump

down and place tube in fluid to be drawn through.

14.4.6.6 PVC (clear) and Duraprene (tan color) pump tube can be used

can be used for this method

14.4.6.7 Place all tube ends in reagent water and run the reagent water

through all the line for at least 5 minutes to check for leaks and

flush potential contaminants.

14.4.7 The method requires a heating unit. Make sure the heater is turn at 60°C and

it has reached at that temperature.

14.4.8 Check that the wash bath line for the auto samples valves is in reagent water.

14.4.9 Load rack with the run sequence (Section 23.1)

14.4.10Switch reagent tube lines from the reagent water to their proper reagent

bottles and allow the system to equilibrate until stable baseline is achieved.

14.4.11 Select PREVIEW and wait for a stable baseline.

14.4.12 Select the STOP function.

14.4.13 Begin the analysis by selecting the START function.

Note: If sample concentration are greater than the high standard, the

distilled sample should be diluted with 0.25M Sodium Hydroxide (NaOH)

diluent. Do not dilute samples or standard with reagent water.

15.0 DATA ANALYSIS AND CALCULATION

15.1 Prepare a calibration curve by the peak area of distilled standard against

concentration values. The data system will then prepare a calibration curve by plot

15.2 Compute sample concentration by comparing sample response with the standard

curve. Result obtained by the instrument is in mg/L. Multiply answer by appropriate

dilution factor. Result can be reported in mg/L and µg/L.

15.3 Report only those values that fall between the lowest and the highest calibration

standards

15.4 Calculations: (For manual demonstration only. QuickChem Software will perform

these calculations automatically)

15.4.1 Spike % Recovery

%R = Cs – C x 100

S

where: R = Percent Recovery

Cs = Average result of analysis of spiked sample and duplicate

C = Average result of the sample without spike

s = Concentration of spike added to sample

15.4.2 Relative % Difference (RPD) Between Spikes:





REVISION: C


RPD = |(Spike Result – Spike Duplicate Result) | x 100

(Spike Result + Spike Duplicate Result)/2

15.5 Calculation of mg CN-/L of Cyanide Standard Stock Solution

Mg/L CN-/L = (A-B) x 1000 X ____ 250______

mL original sample mL portion used

A = mL AgNO3 for sample; B = mL AgNO3 for blank

15.6 For manual integrations (if needed to be performed) refer to SOP ST 001

16.0 METHOD PERFORMANCE

16.1 Refer to laboratory Method Quality Performance Data file.

17.0 POLLUTION PREVENTION

17.1 Pollution Prevention should be the management first option.

17.2 When wastes cannot he feasibly reduced at the source recycling is the next best

option.

18.0 DATA ASSESMENT AND ACEPTANCE CRISTERIA FOR QUALITY CONTROL

MEASURES

18.1 See Procedure ALQAP DW 006-Statistical Control Procedure, Section 23.2 –Table

2- Acceptances Criteria

19.0 CORRECTIVE ACTIONS FOR OUT-OF-CONTROL DATA

19.1 See Procedure ALQAP DW 008- Corrective and Preventive Actions.

20.0 CONTIGENCIES FOR HANDLING OUT –OF-CONTROL OR UNACCEPTABLE

DATA

20.1 See Procedures ALQAP DW 006 – Statistical Control Procedure, ALGAP DW 002

– Procedure of Non-Conforming Results, ALQAP DW 008 – Corrective and

Preventive Action Procedure

21.0 WASTE MANAGEMENT

21.1 Excess reagent, samples and method process wastes should be characterized and

disposed in an acceptable manner.

21.2 See Procedures ALGAP DW 004 – Laboratory Waste Disposal, ALGAP DW 012

– Sample Storage and Disposition.

22.0 REFERENCES

22.1 Lachat Quick Chem 8500 Autoanalyzer Operations Manual

22.2 Quikchem Method 10-204-00-1-A

22.3 USEPA Method 335.4

22.4 Standard Method for the Examination of Water and Wastewater 4500-CN- (22nd

Edition)





REVISION: C


22.5 Environmental Express MicroBlock Distillation System Operation and Instruction

Manual

22.6 ISO 17025 Quality Standard

22.7 Puerto Rico Dept. of Health Regulation for Drinking Water – Manual for the -

Certification of Laboratories Analyzing Drinking Water PRDOH-016-8-90

23.0 TABLES, DIAGRAMS, FLOWCHARTS

23.1 Table 1 - Run Sequence

Sample or Standard Concentration (mg/L)

Calibration Blank 0.00

Calibration Standard Solution A (Lowest Concentration) 0.300

Calibration Standard Solution B 0.100

Calibration Standard Solution C 0.0500

Calibration Standard Solution D 0.0300

Calibration Standard Solution E 0.0100

Calibration Standard Solution F (Highest Concentration) 0.0500

Calibration Blank 0.00

Quality Control Sample 0.0500

Initial Instrument Performance Check 0.0300

Initial Calibration Blank <MDL

Instrument Blank <MDL

Reporting Limit Verification (MRLV) 0.0500

Laboratory Reagent Blank <MDL

Laboratory Reagent Blank Duplicate <MDL

Laboratory Fortified Blank 0.0300

Laboratory Fortified Blank Duplicate 0.0300

On-going Precision & Recovery 0.0500

Method Blank <MDL

Continuance Instrument Performance Check 0.0300

Continuance Calibration Blank <MDL

Sample 1 Unknown

Sample 2 Unknown

Sample 3 Unknown

Sample 4 Unknown

Sample 5 Unknown

Sample 6 Unknown

Sample 7 Unknown

Sample 8 Unknown

Sample 9 Unknown





REVISION: C


Sample or Standard Concentration (mg/L)

Continuance Instrument Performance Check 0.0300

Continuance Calibration Blank <MDL

Sample 10 Unknown

Sample 10 Duplicate Unknown

Sample 10 Spike Unknown + Known Standard

Concentration

Sample 10 Spike Duplicate Unknown + Known Standard

Concentration

Calibration Verification Standard 0.0300

Calibration Verification Blank <MDL

Note: After quality control sample for every 10 sample an instrument performance check

and calibration blank should be performed

23.2 Table 2 – Acceptance Criteria

Parameter Frequency Acceptance Criteria

Method Blank or Laboratory

Reagent Blank (LRB)

1 Method Blank per set of

20 samples or less Must be below MDL value

Laboratory Fortified Blank

(LFB)

Performed 1 with Duplicate

with each batch of sample Recovery % 90.0-110.0%

Standard Calibration Curve

Performed with every

analysis for sample

calculations

Correlation Coefficient

> 0.995. Percent of Recovery of each

standard must be within 90-110% of

it true value.

Calibration Verification

Standard (IPC)

Performed with every

analysis for calibration

preparation verification

Recovery % 90.0-110.0%

Instrument Performance

Check Solution (IPC)

Mid-Range Check Standard

analyses with calibration

blank, immediately

following daily calibration

and after every tenth

sample.

Recovery % 90.0-110.0%

Laboratory Fortified Sample

Matrix (LFM) OR Sample

Spiking

Performed in duplicate on

10% of samples to be

analyzed with every

analysis.

Relative Percent Difference Between

Spikes &

Percent of Recovery of Spike - Refer

to Laboratory Control Limit. Relative

Percent Difference Between Sample

Must be ≤ 20%





REVISION: C


23.3 Figure 1 – MicroBlock Equipment Wiring Connection

Parameter Frequency Acceptance Criteria

Method Detection Level

(MDL)

Initial Determination,

verified every six months,

new analyst performing the

method and/or when a

significant change in

instrument response is

detected

Average of the seven aliquots cannot

exceed 10 time the MDL value.

Linear Calibration Range

(Dynamic Range)

Initial Determination for

method and verified every

six months

Linearity Correlation Coefficient >

0.995

Standards Recovery 90.0-110.0%

Quality Control Standard

(QCS)

(External Source)

Initial Determination for

method and verified every

six months

Recovery 90.0-110.0%





REVISION: C


23.4 Figure 2 – MicroBlock Glassware





REVISION: C


23.5 Figure 3 – Macro Distillation System





REVISION: C


23.6 Figure 4 – LACHAT Cyanide Manifold Setup

Carrier: 0.25M Sodium Hydroxide Solution (Section 10.2.2)

Manifold Tubing: 0.80 mm (0.032 in) i.d. This is 5.2µL/cm

Sample Loop: 50 cm x 0.8mm

Interference Filter: 570nm

Apparatus: An injection valve, a 10mm path length flow cell, and a

colorimeteric detector module are required. The

shows 650cm of tubing wrapped around the heater block at

the specified temperature.

4.5: 70cm of tubing on a 4.5cm coil supoort.

Note 1: 200cm backpressure loop, 0.52mm





REVISION: C


23.7 Figure 5 – Valve Diagrams

23.8 Appendice 1- Cyanide LACHAT Data System Parameters

Sample throughput: 90 sample/h, 40 s/sample

Pump Speed: 35

Cycle Period: 40

Analyte Data:

Concentration units: mg CN-/L

Chemistry: Direct

Calibration fit Type: 1st Order Polynomial

Weighting Method: 1/X

Force through zero: No





REVISION: C


24.0 CHANGE HISTORY

10/04/13 REV. A First Issue

09/04/14 REV. B Correction of all quality manual procedure id used as

reference.

09/19/16 REV. C 1. Add Section 6 (Definition) the definition Initial

Demonstration of Capability, and Minimum Reporting Limit

2. Improved detail related to Initial Demonstration of

Capability in section 12.1.2.

3. Improved detail to each section of Laboratory Performance

(Section 12.2). Also added method requirement for

Minimum Reporting Limit (Section 12.2.5) and Quality

Control Sample (Section 12.2.6).

4. Added to section 13.0 (Calibration & Standardization)

acceptable criteria for calibration curve standard (Section

13.10)

5. Added to Table 1 – Run Sequence (Section 23.1) Reporting

Limit Verification standard.

6. Added to Table 2 – Acceptance Criteria (Section 23.2)

Instrument Performance Check Solution (IPC) and Quality

Control Standard requirement.

7. Added and detailed procedure for the uses of Macro

Distillation System (Section 14.3).

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