National Institute for Occupational Safety and Health

“ Connect the Chromosorb tube to the cassette with a short piece of tubing. Connect the tube to the pump with backup section nearest the sampling pump with flexible tubing. Sample at an accurately known flow rate between 0.5 and 1 L/min for a total sample size of 12 to 400 L. Remove the cassette from the sampling train, carefully remove the filter from the cassette with tweezers and place it in a clean vial. Reassemble the cassette and plug the inlet and outlet. Score the Chromosorb tube in front of the front section and break the tube at score line. ”

“ Transfer the front (larger) section of sorbent and the glass wool plug to the scintillation vial containing the filter. Cap the ends of the sampling tube containing the backup section and ship along with the sample vial. In a separate package, ship bulk sample of the suspected material in a vial.
SAMPLE PREPARATION: 8. 9.
Transfer the backup sorbent section and associated glass wool plugs to a clean vial. Add 5.0 mL toluene to each vial (filter + front sorbent section in one vial and back sorbent section in another vial) . Cap each vial. Allow to stand, with occasional swirling, for 15 min. ”

“ Calibrate daily with at least six working standards covering the range of samples. a. Add known amounts of calibration stock solution to toluene in 10-mL volumetric flasks and dilute to the mark. Use serial dilution as needed to obtain endrin concentrations in the range 0.004 to 7 μg/mL. b. ”