National Institute for Occupational Safety and Health

“ Calculate recovery (ethylene glycol recovered/ethylene glycol taken) . Determine DE from silica gel for each lot of silica gel in the range of interest. Prepare three tubes at each of five levels plus three media blanks. a. Draw ethylene glycol vapor with a pump at 0.2 L/min into sampler tubes with a pump from a U-tube partly immersed in a constant temperature bath at 75 °C. NOTE: Values of DE for liquid and vapor spikes may be different [3] . b. Desorb (steps 5 and 6) and analyze (steps 10 through 12) together with working standards. c. Prepare a graph of DE vs. mg ethylene glycol recovered. ”

“ Gas chromatograph, FID, integrator and column (page 5500-1) . 4. Vials, glass, 1-mL, rubber caps. 5. Syringes, 10-μL, readable to 0.1 μL. 6. U-tube, glass, 25 cm x 15-mm ID. 7. Constant temperature bath, 75 °C. 8. ”