National Institute for Occupational Safety and Health

“ Seal and gently swirl the jar to wet the filter. Let stand 30 min with occasional swirling. Filter the sample solution through a syringe filter.
CALIBRATION AND QUALITY CONTROL: 6.
7.
Calibrate daily with at least six working standards over the range 0.01 to 1.8 mg pyrethrum per sample. a. Add known amounts of calibration stock solution, or a dilution thereof, to acetonitrile in 10-mL volumetric flasks and dilute to the mark. b. Analyze together with the samples and blanks (steps 9, 10 and 11) . c. Prepare calibration graph (peak area vs. mg pyrethrum/10 mL) . ”

“ Pyrethrum*, analytical standard solution (McLaughlin Gormley King Co., Minneapolis, MN; Chem Service, Inc., West Chester, PA; or other supplier) . NOTE: Store away from direct light. Active constituents of pyrethrum oxidize in air and photodecompose. Acetonitrile, HPLC grade.* Water, HPLC grade. Isopropanol. Calibration stock solution,* 60 mg/mL, in isopropanol.
1.
2. 3.
4. 5. 6. 7. 8. 9.
Sampler: 37-mm glass fiber filter and cellulose backup pad in filter holder held together with tape or shrinkable band. Personal sampling pump, 1 to 4 L/min, with flexible connecting tubing. ”

“ NIOSH/OSHA Occupational Health Guidelines for Chemical Hazards, U.S. Department of Health and Human Services, Publ. (NIOSH) 81-123 (1981) , available as GPO Stock #017-033-00337-8 from Superintendent of Documents, Washington, DC 20402. ”