National Institute for Occupational Safety and Health

“ Attach sampler to personal sampling pump with flexible tubing. Sample at an accurately known flow rate of 0.2 ±0.03 L/min for a total sample size of 6 to 30 L. Cap the samplers. Pack securely for shipment.
SPECIAL PRECAUTIONS: Carbon disulfide is toxic and a serious fire and explosion hazard (flash point = -30 °C) ; all work with it must be done in a hood away from ignition sources. Diazomethane is an explosive, insidious poison and a strong irritant which may cause delayed hypersensitivity and cancer [3] . Concentrated solutions may explode violently, especially if impurities are present. ”

“ Determine desorption efficiency (DE) at least once for each lot of coated XAD-2 resin used for sampling in the calibration range (step 8) . Prepare three tubes at each of five levels plus three media blanks. a. Remove and discard back sorbent section of a media blank sampler. b. Inject a known amount of methyl octanoate directly onto front sorbent section with a microliter syringe. c. Cap the tube. Allow to stand overnight. d. Desorb (steps 5 through 7) and analyze with working standards (steps 11 and 12) . e. Prepare a graph of DE vs. μg methyl octanoate recovered. ”

“ Sample stability was not determined. The method does not meet the 10% bias criterion for a valid NIOSH method. Breakthrough of the front section of the coated XAD-2 tube was not observed after sampling 53 L of dry test atmosphere containing 0.83 mg/m 3 for 240 min at 0.22 L/min. Desorption efficiencies for samples spiked with methyl octanoate were 1.01 to 1.05. The collection efficiency and reaction of diazomethane with the octanoic acid-coated resin may be strongly dependent on sample flow rates; therefore, all samples must be collected at a flow rate of 0.2 L/min only. ”