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2311635 
Technical Report 
Sampling For Mercaptans By Absorber Tubes 
Nathans, MW; Jeong, A 
1980 
NIOSH/00154053 
ACS Symposium Series No 
120 
231-239 
A sampling method for mercaptans was described and tested. An absorber tube containing two plugs of glass wool was constructed. One plug was wetted with a solution containing mercuric-acetate in water mixed with glacial-acetic-acid. The second plug was inserted and wetted with the absorbing solution. The pressure drop across 24 samples was determined. Air was pumped through the tubes at a rate of 300 milliliters per minute (ml/minute). The flow rate was measured at constant pressure drop. Atmospheres with known concentrations of methyl-mercaptan (74931) were generated and sampled. The effect of storage was determined. Plugs were removed from the tubes and analyzed colorimetrically. The mean pressure drop was 37.7 millimeters mercury (mm Hg). At a constant pressure drop of 20.5mm Hg the flow rate was 292ml/minute. Sampling with impingers gave results that were about 10 percent below those using the absorber tubes. The best results were obtained with samples stored for 14 days or less. The authors conclude that the method is not specific for individual mercaptans. The use of gas chromatography is expected to make the method specific.