National Institute for Occupational Safety and Health

“ Remove and discard back sorbent section of a media blank sampler. b. Inject a known amount (2 to 20 μL) of calibration stock solution, or a serial dilution thereof, 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 2-nitropropane recovered. Analyze three quality control blind spikes and three analyst spikes to ensure that the calibration graph and DE graph are in control. ”

“ SPECIAL PRECAUTIONS: 2-Nitropropane is a suspected human carcinogen [4] . Perform all work with this chemical in a 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 sampler to personal sampling pump with flexible tubing. Sample at an accurately known flow rate between 0.01 and 0.05 L/min for a total sample size of 0.1 to 2 L. NOTE: High pressure drop across the sampler may occur at flow rates 0.05 L/min, giving inaccurate sample volumes. ”

“ CALIBRATION AND QUALITY CONTROL: 8.
Calibrate daily with at least six working standards. a. Add known amounts of calibration stock solution to ethyl acetate in 10-mL volumetric flasks and dilute to the mark. ”