On-line membrane extraction microtrap GC system for continuous monitoring of organic pollutants in air and water

Somenath Mitra, Lizhong Zhang, Naihong Zhu

Research output: Contribution to journalConference articlepeer-review

4 Scopus citations


A membrane sampling technique has been developed for continuous on-line monitoring of volatile organic compounds (VOCs) in water and in air. The VOCs can be sampled by passing the air/water continuously through a membrane hollow fiber. Organic pollutants selectively permeate through the membrane and are stripped by a flowing N2 stream. The analytes are transferred to a microtrap, which is a microbore stainless steel tubing packed with a solid sorbent. The organics are trapped and concentrated in the microtrap. A pulse of electric current is used to heat the microtrap in a short time (0.8 approx. 1.2 sec.) to desorb the analytes as a concentration pulse which serves as an injection for GC separation. Continuous monitoring is accomplished by passing the air/water sample through the membrane and making microtrap injections at fixed intervals. Corresponding to each injection, a chromatogram is obtained. The system has detection limits at the ppb levels for most VOCs in both air and water. Linear calibration curves were obtained for both air and water. The advantages of membrane sampling is that it cab be fast, simple, and suitable for on line continuous monitoring.

Original languageEnglish (US)
Pages (from-to)1-7
Number of pages7
JournalISA TECH/EXPO Technology Update Conference Proceedings
Issue numberpt 2
StatePublished - Jan 1 1995
Externally publishedYes
EventProceeding of the 1995 International Conference, Exhibition ISA/95 - New Orleans, LA, USA
Duration: Oct 1 1995Oct 6 1995

All Science Journal Classification (ASJC) codes

  • Instrumentation
  • Condensed Matter Physics


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