National Institute for Occupational Safety and Health

“ Determine the mass, μg (corrected for R) of TNF found in the sample (W) and in average media blank (B) . Calculate concentration, C, of TNF in the air volume sampled, V (L) :
EVALUATION OF METHOD: Lab-tested with 2,4,7-trinitrofluoren-9-one spiked filters. The average recovery was 95% over the range 0.2 to 4.0 μg per sample and had a pooled precision ( Sr) of 0.056. PTFE filters with a loading of 0.4 μg were stored for two weeks at room temperature with no loss of analyte [1,2] . ”

“ Remove cassette plugs and attach cassette to personal sampling pump with flexible tubing. Sample at an accurately known flow rate between 1 and 3 L/min for a total sample size of 100 to 500 L. Plug the inlet and outlet of the cassette. Pack securely for shipment.
SAMPLE PREPARATION: 5. 6. 7. 8. 9.
Remove filter from cassette. Fold or roll the filter and slide it to the bottom of a test tube with tweezers. Add 2.0 mL toluene to each test tube and seal. Suspend test tube with filter in an ultrasonic bath. Agitate for 5 min. Centrifuge sample at ca. ”

“ Toluene. Calibration stock solution, 0.05 mg/mL. Dissolve 0.5 mg 2,4,7-trinitrofluoren-9-one* (TNF) * in 10 mL toluene.
See SPECIAL PRECAUTIONS. 1. Sampler: PTFE filter, 0.5-μm pore size, 37-mm diameter, with backup pad and in polystyrene cassette. 2. Personal sampling pump, 1 to 3 L/min, with flexible connecting tube. 3. Liquid chromatograph with UV detector, recorder, integrator, autosampler or syringe, and column (page 5018-1) 4. Ultrasonic waterbath. 5. Centrifuge. 6. Test tubes, glass, 10-mL, screw-cap. 7. Pasteur pipets. 8. ”