Page:NIOSH Manual of Analytical Methods - 6010.pdf/2

 HYDROGEN CYANIDE: METHOD 6010, Issue 2, dated 15 August 1994 - Page 2 of 5 REAGENTS: 1. 2. 3. 4. 5. 6. 7. 8. 9.

10. 11. 12.

13. 14.

15.

EQUIPMENT:

Potassium cyanide*, reagent grade. Succinimide, reagent grade. N-Chlorosuccinimide, reagent grade. Barbituric acid, reagent grade. Pyridine, spectrophotometric quality. Phenolphthalein, 1% (w/v) in ethanol or methanol, reagent grade. Hydrochloric acid, concentrated, reagent grade. Sodium hydroxide (NaOH), reagent grade.* Sodium lime (CaO + 5-20% NaOH), reagent grade (Aldrich #26,643-4 or equivalent). Crush and sieve to 10/35 mesh. Store in capped container.* Water deionized-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 50mL volumetric flask. Dilute to mark with 0.1 N NaOH. Standardize by titration with standard AgNO3 solution (see APPENDIX). Hydrochloric acid solution, 0.15 N. N-Chlorosuccinimide/succinimide oxidizing reagent. Dissolve 10.0 g succinimide in about 200 mL distilled water. Add 1.00 g Nchlorosuccinimide. Stir to dissolve. Adjust volume to 1 liter with distilled water. Stable 6 months when refrigerated. Barbituric acid/Pyridine reagent. Add about 30 mL distilled water to 6.0 g barbituric acid in a 100-mL Erlenmeyer flask. Slowly add 30 mL pyridine with stirring. Adjust the volume to 100 mL with water. Stable 2 months when refrigerated.

1. Sampler, 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 inlet side. Tubes are commerically available. (SKC, Inc. 226-28 or equivalent.) 2. Spectrophotometer, visible, 580 nm, with cuvettes, 1-cm light path. 3. Personal sampling pump, 0.05 to 0.2 L/min, with flexible connecting tubing. 4. Pipets, volumetric 0.1-, 0.5-, 1.0-, 2.0-, 10.0-mL. 5. Vials, glass or plastic, 15-mL with PTFE-lined caps. 6. Flasks, volumetric, 25-, 50-, 100-, 1000-mL, with stoppers. 7. Pipets, transfer, disposable. 8. Syringes, 10-µL, readable to 0.1 µL. 9. Flask, Erlenmeyer, 100-mL. 10. Syringes, 10-mL, polyethylene with luer tip. 11. Filter cassette, with membrane filter, 13-mm diameter, 0.45-µm pore size, with luer fitting.
 * See SPECIAL PRECAUTIONS

SPECIAL PRECAUTIONS: HCN gas and cyanide SAMPLING: particulates are highly toxic and may be fatal if swallowed, inhaled, or absorbed through the skin 1. Calibrate each personal sampling pump [5]. Soda lime and NaOH are very caustic [5]. with a representative sampler in line. Use gloves and a fume hood for handling these 2. Break ends of sampler immediately before chemicals. sampling. Attach sampler to personal sampling pump with flexible tubing. 3. Sample at an accurately known flow rate between 0.05 and 0.2 L/min for a total sample size of 0.6 to 90 L. 4. Cap tube. Pack securely for shipment.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94