EFFECTS OF SILCOSTEEL(R) TRANSFER LINE ON THE SAMPLING OF VOLATILE ORGANIC-COMPOUNDS

A 150-ft section of 1/16-in. o.d. x 0.030-in i.d. fused-silica-lined s tainless tubing (Silcosteel(R)) was studied to determine its suitabili ty as a transfer line in the sampling and analysis of vapor samples of Volatile organic compounds (VOCs), principally in subsurface soil gas es. A variety of test atmospheres of individual VOCs at concentrations ranging from 0.01 to 10,000 ppm were used to challenge the tubing. Th e adsorptive and desorptive properties of the tubing were characterize d under conditions [14 degrees C (57 degrees F) end 90% RH] comparable to subsurface environments and also at temperatures of 2 degrees C (3 5 degrees F) and 46 degrees C (115 degrees F). Clearance rates of the selected VOCs from the tubing were also determined. Direct-sampling io n-trap mass spectrometry (DS-ITMS) real-time air monitoring was used t o measure the effects of the transfer line on the vapor samples. (C) 1 998 John Wiley & Sons, Inc.