National Institute for Occupational Safety and Health

“ Inject a 1-μL sample aliquot manually using the solvent flush technique or with an auto sam pler. Note: If peak a rea is above the linear range of the working standards, dilute with solvent, reanalyze and app ly the app ropriate dilution facto r in the c alculations. 12. Measure peak areas.
CALCULATIONS: 13. Determine the mass, μg (corrected for DE ) , of acetoin found in the sam ple front (W f) and back (W b) sorbent sections, and in the average m edia blank front (B f) and back (B b) sorbent sections. Note: If W b > W f/10, report b reak throu gh a nd p oss ible sam ple loss. 14. ”

“ Cap the samplers with plastic caps, pack in a manner to insure that the sam plers are kept in the dark, and are s hipped c old (5°C) .
SAMPLE PREPARATION: 5. Place the front and back sorbent sections in separate amber vials. Place the glass wool plug preceding the front section into the vial containing the front sorbent section. Discard the urethane foam plugs. 6. Add 1.0 mL of the acetone/methanol (95:5) solvent into each vial. Securely attach crimp caps to each vial. 7. Plac e ea ch vial on a rotary m ixer fo r 1.5 hours . ”

“ W eigh out a know n am ount of acetoin in a 10-m L volum etric flask a nd dilute to the m ark with solve nt. Prepare add itional standa rds by serial dilution in additional 10-m L volum etric flas ks. b. Analyze together with samp les and blanks (steps 11 and 12) . c. Prepare c alibration graph (pe ak area vs μg ace toin) . 9. Determine the desorption efficiency (DE) at least once for each lot of Anasorb CMS used for sampling in the c alibration rang es (s tep 8) . a. Prepare three tubes at each of five levels plus three media blanks. ”