Direct diffusion sampling-based photoacoustic cell for in situ and on-line monitoring of benzene and toluene concentrations in water

A. Mohácsi, Z. Bozóki, R. Niessner

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Photoacoustic (PA) sensor for in situ and on-line concentration monitoring of toluene and benzene in water is being discussed. Selective detection was accomplished by transferring (by means of a permeable membrane) the analyte of interest into the gas phase. Unlike what is encountered in the conventional approach, where sampling and detection unit are separated, here the membrane is inserted directly into the central part of the photoacoustic resonator, eliminating thereby the need for various gas-handling components as well as the use of a purging gas. In this way, the system becomes simpler, more compact, with a response time of 40min and a potential for fully automated operation. The use of a near-infrared (1.67 μm) diode laser coupled to the PA cell by an optical fibre resulted in detection limits of 350μg (for benzene) and 1.1mg (for toluene) per 1l of water. When placed directly into water wells, the proposed sensor can serve as a warning system for long-term and automatic observation.

Original languageEnglish
Pages (from-to)127-131
Number of pages5
JournalSensors and Actuators, B: Chemical
Volume79
Issue number2-3
DOIs
Publication statusPublished - Oct 15 2001

Keywords

  • BTX
  • Environmental
  • On-line
  • Permeable
  • Photoacoustic
  • Water pollution

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry

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