National Institute for Occupational Safety and Health

“ The method was evaluated for six glycols (ethylene, propylene, 1,3-butylene, diethylene, triethylene, and tetraethylene) . Desorption efficiency (DE) was determined by spiking known amounts of each glycol in methanol solution onto the glass fiber filter plug of the XAD-7 OVS tubes, drawing air through the spiked tubes at 1 L/min for 60 min, and analyzing. Recovery data along with LODs and LOQs for each analyte are listed in Table 2. When stored at 5 C, ethylene glycol samples on XAD-7 OVS tubes were stable for 14 days, and the other glycols were stable up to 28 days. ”

“ Add known amounts of calibration stock solution to methanol in 10-mL volumetric flasks and dilute to the mark. b. Analyze together with samples and blanks (steps 11 and 12) . c. Prepare calibration graph (peak area or height vs. μg glycol) . 9. Determine desorption efficiency (DE) at least once for each lot of OVS tubes used for sampling in the calibration range (step 8) . a. Prepare three samplers at each of six levels plus three media blanks. b. Inject a known amount of calibration stock solution directly onto the filter of OVS tubes. ”

“ Ethylene glycol, reagent grade.* Propylene glycol, reagent grade.* 1,3-Butylene glycol, reagent grade.* Diethylene glycol, reagent grade.* Triethylene glycol, reagent grade.* Tetraethylene glycol, reagent grade.* Methanol, chromatographic grade.* Calibration stock solution, 10 mg/mL: Weigh aliquots of each glycol and dissolve in methanol. 9. Helium, purified. 10. Hydrogen, prepurified. 11. Air, filtered.
See SPECIAL PRECAUTIONS SPECIAL PRECAUTIONS: Inhalation of glycol mists causes respiratory irritation, shortness of breath, and coughing. Methanol is flammable and a dangerous fire risk. ”