Supercritical Fluid Extraction-Gas Chromatography of Volatile Organic Compounds (VOC) from Tenax Devices

摘要

The report describes the development and evaluation of on-line supercritical fluid extraction-gas chromatography instrumentation and methodology for the analysis of volatile organic compounds (VOC) from adsorbent sampling devices. Supercritical fluid extraction offers potential advantages for the removal and transport of organic components from adsorbent matrices including rapid and efficient extraction at mild temperatures. Extraction at mild temperatures eliminates potential problems such as analyte decomposition that can be encountered with the high temperatures needed for thermal desorption analysis. Since a major objective of the study was to develop viable instrumentation and methodology, a relatively detailed description of the instrumentation design requirements and present limitations are discussed. The results of several series of methodology validation studies are also presented. These studies included recovery studies of model VOC spiked on three types of Tenax sampling devices including authenic actively pumped (VOST) and passive (EPA) devices. Replicate devices spiked in an exposure chamber were also subjected to parallel analyses using the new methodology and traditional thermal desorption gas chromatography.