National Institute for Occupational Safety and Health

“ Calibrate daily with at least seven working standards. a. Prepare standards in capped vials by mixing various volumes (i.e., 5 to 230 μL) of calibration stock solution with carbon disulfide to a total volume of 4.00 mL to obtain concentrations in the range of 0.010 to 5 mg/mL. b. Analyze together with samples and blanks (steps 11 and 12) . Determine the desorption efficiency (DE) at least once for each lot of charcoal used for sampling in the calibration range (step 8) . Prepare three tubes at each level plus three media blanks. a. Use the 400-mg charcoal tube for DE determination. ”

“ Carbon disulfide is also toxic. Work with these compounds in a hood.
SAMPLING: 1. 2. 3. 4.
Calibrate each personal sampling pump with a representative sampler in line. Immediately before sampling, break ends of sampler tubes. Connect smaller tube to personal sampling pump with flexible tubing and to larger tube with a short piece of plastic tubing. Sample at an accurately known flow rate of 0.1 to 0.2 L/min for a sample size of 2 to 96 L. Separate the tubes, cap, and pack securely for shipment. Chilling of the samples is necessary if they are not expected to be analyzed within five days. ”

“ A five-day room-temperature stability study at 415 μg MTBE in gasoline spiked in 400 mg charcoal tubes indicated a 100.0 ± 4.6% recovery. Four charcoal tubes spiked with 415 μg MTBE in gasoline had air drawn for six hours at 100 mL/min and then were stored at -7 °C for five days indicating 103.6 ± 9.0% recovery. No sample loss occurred due to breakthrough at the 415-μg per sample MTBE level. Charcoal tubes which were spiked with 10 mg MTBE in gasoline and which had 6 to 78 L of air drawn through them did not indicate any breakthrough of MTBE. Light hydrocarbons i.e. ”