National Institute for Occupational Safety and Health

“ Allow solve nt to evaporate. b. Store samples overnight in filter cassettes. c. Prepare and analyze with working standards. d. Prepare a graph of R vs. μg mineral oil recovered. 7. Analyze three quality control blind spikes and three analyst spikes to ensure that the calibration graph and R g raph are in control.
MEASUREMENT: 8. Scan each standard solution and each blank or sample filter extract from 3200 to 2700 cm -1 in absorbance mode vs. CCl4 in reference beam. Record absorbance at wavelength of largest absorbance near 2940 cm -1 (± 11.8% ) . ”

“ Stoc k m ineral oil standards , 20 m g/m L. W eigh 1.0 g of the bulk m ineral oil sam ple into a 50-m L volum etric flas k. D ilute to volume with CCl4. Prepare in duplicate.
See SPECIAL PRECAUTIONS 1. Sam pler: mem brane filter, 37-mm , 0.8-:m MCE, 5-:m PV C, 2-:m PT FE, or glass fiber filter, with cellulose backup pad in two-piece filter cassette. NOT E 1: High concentrations of oil mist may plug m em brane filters. Glass fibers filters have a higher capacity for oil mist and mem brane filters. NOT E 2: Hand le filters carefully with tweezers to avoid contam ination by skin oil. 2. ”

“ They have lower blanks than PVC, since PTFE has fewer extractables with CCl4 than other mem brane filters.
REFERENCES: [1] [2] [3] [4] [5]
Docum entation of the NIOSH Validation Tests, S272, U.S. Department of Health, Education, and W elfare , Pub l. (NIO SH ) 77-185 (197 7) , available a s PB 274 -248 from NT IS, Sp ringfield, VA 22161. Bolyard, M L. Infrared Quantitation of Mineral Oil Mist in Personal Air Samples, AIH Conference, Hous ton, TX (19 80) . NIOSH M anual of Analytical Methods, 2nd ed., Vol. 4, P&CAM 283, U.S. Department of Health, Educa tion, and W elfare, Publ. ”