National Institute for Occupational Safety and Health

“ Coast Engineering Laboratory 40/60 mesh silica gel was the collecting medium. Average recovery was 97.1%, representing a non-significant bias. The concentration of 2-diethylaminoethanol was independently verified using midget bubblers containing 15 mL 2% HCl. Desorption efficiency was 0.964 in the range 0.6 to 2.3 mg per sample. Breakthrough (5% on back section) was not achieved after 5.3 h when sampling an atmosphere containing 88 mg/m 3 2-diethylaminoethanol at 0.2 L/min at 82% relative humidity. ”

“ Calibrate daily with at least six working standards over the range 0.005 to 6 mg of each analyte. a. Add known amounts of analyte or calibration stock solution to 0.12 N HCl in eluent in 10-mL volumetric flasks and dilute to the mark. b. Treat the working standards with base and benzaldehyde as needed (steps 9 and 10) . c. Analyze together with samples and blanks (steps 14 and 15) . d. Prepare calibration graph (peak area vs. mg analyte) . Determine desorption efficiency (DE) at least once for each lot of silica gel used for sampling. ”

“ Prepare a graph of DE vs. mg analyte recovered. Analyze three quality control blind spikes and three analyst spikes to ensure that the calibration graph and DE graph are in control.
MEASUREMENT: 14.
15.
Set gas chromatograph according to manufacturer's recommendations and to conditions given on page 2007-1. Inject sample aliquot manually using solvent flush technique or with autosampler. NOTE 1: The temperature program separates all three compounds. Isothermal column conditions are 225, 150, and 90 °C for 2-aminoethanol, 2-dibutylaminoethanol and 2-diethylaminoethanol, respectively. ”