Monitoring VOCs in atmospheric air I. On-line gas analyzers

This article reviews the literature on analytical instruments routinely used for monitoring volatile organic compounds in atmospheric air. We classify the analyzers as stationary or mobile, according to their ease of transport. We describe a stationary differential optical absorption spectroscopy analyzer, and membrane-introduction mass spectrometry (MS), membrane extraction with sorbent interface, ionization at atmospheric pressure or low pressure coupled with tandem MS instruments, into which air samples can be injected directly. We also describe mobile instruments (e.g., automatic analyzers for benzene, toluene, ethylobenzene, and xylenes, portable mass spectrometers and a mobile monitoring system).