Page:NIOSH Manual of Analytical Methods - 6017.pdf/2

 HYD RO GE N C YAN IDE: ME TH OD 6017, Issue 1, dated 1 5 Ma rch 2003 - Page 2 of 5 REAGENTS:

EQUIPMENT:

1. 2. 3. 4. 5.

1.

6. 7. 8.

9.

Potass ium cyanide, rea gen t grad e.* Sodium acetate trihydrate, A.C.S. grade. Ethylenediamine, 99%. Sodium hydroxide (Na OH ), reag ent grade .* Sodium lime (CaO + 5 to20% NaO H), reagent grade (Aldrich #26,643-4, or equivalent). Crush and sieve to 10/35 mesh. Store in capped conta iner.* W ater, deionized or distilled. Sodium hydroxide solution, 0.1 N.* Calibration stock solution. 1 mg/mL CN -: Dissolve 0.125 g KCN in 0.1 N NaOH in a 50-mL volumetric flask. Dilute to mark with 0.1 N NaOH. Standardize by titration with standard AgNO 3 solution (see APPE ND IX). Eluent, 0.5 M sod ium ace tate, 0.1 M N aO H, 0.5% ethylenediamine: Dissolve 60 g sodium acetate + 4 g NaOH pellets in 800 mL H 2O. Add 5 mL ethylenediamine. Bring to 1 L with distilled water.


 * See SPECIAL PRECAUTIONS

2. 3. 4. 5.

6. 7. 8. 9. 10. 11. 12. 13.

Sam pler: Glass tube, 9 cm long, 7-mm OD, 5-mm ID, with plastic caps, containing two sections (front = 600 mg; back = 200 mg) granular soda lime 10/35 mesh, separated and contained with silanized glass wool plugs, with a 5-mm diameter glass fiber filter disk placed before the plug on the inlet side (SKC, Inc. 226-28, or equivalent). Personal sampling pump, 0.05 to 0.2 L/min, with flex ible conne cting tubing. DIONEX DX-500 or equivalent ion chromatograph. DIONEX ED-40 or equivalent electrochem ical detector. DIO NE X or equ ivalent a m pero m etry cell with silver working electrode and silver chloride reference. DION EX A S7 colum n with AG7 guard colum n or e quiva lent. Autosam pler. Autosampler vials. Vials, 15- to 20-mL, for sample preparation. In-line filters, 0.45-µm. Micropipettors with disposable tips. Flasks, volumetric, 25-, 50-, 100-, 1000-mL, with stoppers Pipettes, transfer, disposable.

SPECIAL PRECAUTIONS: HC N gas and cyanide particu late s are highly toxic and m ay be fa tal if swallowed, inhaled, or absorbed through the skin [7]. Soda lime and NaO H are very caustic [7]. Use gloves and a fume hood when handling these chemicals.

SAMPLING: 1. Calibrate each personal sampling pump with a representative sampler in line. 2. Break end s of s am pler im m ediately before sa m pling. Attach sam pler to p ersona l sam pling pum p with flexible tubing. 3. Sam ple at a n ac curately kn own flow ra te betwee n 0.05 an d 0.2 L/m in for a total sam ple size of 0.6 to 90 L. 4. Ca p tube. Pa ck sec urely for shipm ent.

SAMPLE PREPARATION: 5. Score each sampler with a file. Break sampler at score line. 6. Transfer front and back sorbent sections to separate vials. Discard glass wool plugs separating and retaining sorbent sections. NOTE: An estimate of particulate cyanide may be obtained by analyzing the initial glass fiber filter disk as follows; however, no evaluation data are available for particulate cyanides determined in this m anner: a. Trans fer the glass fiber disk a nd glass woo l plug im m ediately behind it at the tube inlet to a third vial. b. Ad d 10.0 m L 0.1 N Na OH to each vial. c. Proceed with step 8. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition