Detection and analysis of volatile organic chemicals in waste water using an electronic nose

This paper describes use of a new type of electronic nose, called the zNose (R) for measurement of volatile organic compounds in water. Based upon ultra-fast gas chromatography, the zNose (R) is able to perform analytical measurements of volatile organic vapors in near real time with part-per-billion sensitivity. Separation and quantification of the individual chemicals within water samples is performed in seconds. Using a patented solid-state mass-sensitive detector, picogram sensitivity, universal non-polar selectivity, and electronically variable sensitivity is achieved. An integrated vapor pre-concentrator coupled with the electronically variable detector allow the instrument to measure VOC concentrations spanning 6+ orders of magnitude. Using the electronic nose an on-site procedure for measuring the concentration of VOCs in water based on headspace analysis is described. Measurement of volatile chemicals in water headspace vapors is correlated with water standards using Henry's Law. Use of this instrument and procedure for aniline and nitrobenzene contaminated water is described. The real time measurement technique has recently been used to measure the concentrations of aniline and nitrobenzene in the Songhua River caused as a result of an explosion at a petrochemical plant in northeastern China. The ease and economics of real time on-site measurements has direct financial benefits.