Page:NIOSH Manual of Analytical Methods - 6012.pdf/2

 SULFURYL FLUORIDE: METHOD 6012, Issue 1, dated 15 August 1994 - Page 2 of 4 REAGENTS: 1. 2. 3.

4. 5.

6.

EQUIPMENT:

Sodium hydroxide*, ACS reagent grade. Water, high purity. Desorbing/extracting solution and eluent: 40 mN NaOH. Dissolve 3.2 g NaOH in 2 L of degassed high purity water. Suppressor regenerant, 25 m N H2SO 4*. Calibration stock solution, 1 mg fluoride anion per mL. Dissolve 0.2210 g NaF in 100 mL deionized water. Sulfuryl fluoride*, gas. Calibrated gas standards may be obtained from Scott-Marrin, Inc., Riverside, CA 92507.



See SPECIAL PRECAUTIONS.

1. Sampler: glass tube, 11 cm long, 10-mm OD, 7-mm ID, flame-sealed ends, containing two sections of activated (600 °C) coconut shell charcoal (front = 800 mg, back = 200 mg), separated by a 2-mm urethane foam plug. A silylated glass wool plug precedes the front section and a 3-mm urethane foam plug follows the back section. Pressure drop across the tube at 1 L/min airflow must be less than 3.4 kPa. Tubes are commercially available. 2. Personal sampling pump, 0.05 to 0.10 L/min, with flexible polyethylene or PTFE tubing. 3. Refrigerant, bagged ("Blue Ice," or equivalent). 4. Filter, membrane, 0.45-µm pore size, 13-mm, with luer fitting. 5. Ion chromatograph, with a conductivity detector, chart recorder, integrator and columns (p. 6012-1). 6. Vials, glass, 20-mL, with plastic caps. 7. Vials, polyethylene, 20-mL, with plastic caps. 8. Micropipettes, with disposable plastic tips. 9. Volumetric flasks, 100-mL 10. Pipet, 10-mL, graduated in 0.1-mL intervals. 11. Pipet, volumetric, 20-mL. 12. Syringes, 10-mL, plastic, with luer tip.

SPECIAL PRECAUTIONS: Sulfuryl fluoride is a restricted use pesticide owing to its inhalation toxicity. It is extremely hazardous as vapor or liquid. Inhalation of vapors may be fatal. Read and follow all label precautions [6]. Sulfuric acid and sodium hydroxide are corrosive to skin, eyes, and mucous membranes. Handle all hazardous chemicals in a fume hood. SAMPLING: 1. 2. 3. 4.

Calibrate each personal sampling pump with a representative sampler in line. Break the ends of the sampler immediately before sampling. Attach a sampler to personal sampling pump with flexible tubing. Sample at an accurately known flow rate between 0.05 and 0.1 L/min for a total sample volume of 1.3 to 10 L. Cap the samplers with plastic (not rubber) caps and pack securely for shipment, at 0 °C.

SAMPLE PREPARATION: 5. 6. 7. 8. 9.

Place the front and back sorbent sections of the sampler tube in separate 20-mL plastic vials. Discard the glass wool and foam plugs. Add 20 mL 40 m N NaOH eluent to each plastic vial. Cap. Sonicate for 60 minutes. Transfer a 5 to 7 mL aliquot to a tare weighted 20-mL glass vial using a plastic syringe fitted with a 0.45 µm membrane filter. Re-weigh each glass vial and contents so that the net weight of the aliquot can be calculated. Take each sample to complete dryness in an uncapped glass vial on a hot plate. Cool, then reconstitute to the original net weight with high-purity water. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94