National Institute for Occupational Safety and Health

“ Prepare a calibration graph of peak height vs. amount (μg) of fluoride per 20 mL of sample. (Optional) . Determine recovery (R) for each lot of tubes used for sampling in the concentration range of interest. Prepare four tubes at each of five levels plus three media blanks. a. Collect a known amount of SO 2F2 gas onto each charcoal tube (steps 1 through 9) . b. Analyze samples in the same manner as field samples (steps 12 through 14) . c. Prepare graph of recovery vs. μg sulfuryl fluoride.
MEASUREMENT: 12. 13. 14.
Set ion chromatograph to conditions given on page 6012-1. ”

“ 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. ”

“ Re-filter sample if necessary, then inject a sample aliquot into the ion chromatograph. Measure peak height.
CALCULATIONS: 15. 16.
Determine mass (μg) of fluoride found on the front (W f) and back (W b) sections, and in the average media blank front (B f) and back (B b) sorbent section. Calculate concentration C of sulfuryl fluoride (mg/m 3) in the actual air volume, V (L) , applying the conversion factor 2.686 (MW SO 2F2/MW F -; the reaction is SO 2F2 + 4NaOH → 2NaF + Na 2SO 4 + 2H 2O) :
EVALUATION OF METHOD: This method was evaluated over the range 20 to 420 mg/m 3. ”