Groundwater contaminants, detection, using

The monoaromatic compounds benzene, toluene, ethylbenzene and xylene, commonly found in crude oil, are often jointly called BTEX compounds. The most harmful of these compounds is benzene, which is a known carcinogen. BTEX compounds occur naturally near natural gas and petroleum deposits and are detected in the fumes of forest fires. Most of the highly volatile BTEX compounds released by human activity originate from fuel use and end up as pollutants in the air. Inhaling BTEX-polluted air is also the greatest hazard to humans by these compounds. BTEX compounds are water-soluble, and therefore, improper handling can also cause groundwater contamination. 

Neumayr [3] carried out soil atmosphere studies using capillary gas chromatography and electron capture and flame ionization sequential detection and used this as a means of pinpointing zones of soil and groundwater contamination. 

Chudyk WA, Carrabba MM, Kenney JE. 1985. Remote detection of groundwater contaminants using far-ultraviolet laser-induced fluorescence. Anal Chem 57 1237-1242. 

Chudyk et al. [IS] reported results obtained in a test of remote fluorescence analysis of groundwater contaminants using UV laser light sources and fiber optics. Several priority pollutants such as phenols, toluene, and xylenes and also naturally occuring humic acid, all of which display UV fluorescence, were readily detected over a distance of 20-25 m. Typical detection limits over this distance are 10 ppb for phenol, 1 ppb for o-cresol, and 0.07 ppb for xylenes. A prototype instrument for monitoring phenolic groundwater contaminants has been described, and its suitability demonstrated by using phenol as a model contaminant [16]. 

The urea pesticides diuron, fluormeturon, neburon and Hnuron cited as potential groundwater contaminants from US EPA in the National Pesticide Survey were quantitatively determined by APCI-LC-MS(-t) [354]. APCI-LC-MS was also used to test for 46 pesticide compounds in shallow groundwater samples from two sandy and two clay catchment areas. Of the neutral polars observed, isopro-turon belonged to the most frequently found compound [351]. Sphid et al. described an APCI-LC-MS method for the determination of isoproturon and different types of pesticides and their degradation products in ground water samples. Detection Umits, recovery, precision and Hnearity data were reported [350]. 

Professor Kenny s research focuses on the use of spectroscopy to analyze samples in the real world. One project involves a vehicle that uses a hydraulic press to insert a small-diameter rod into the ground to depths of 50 m or more. A sapphire window near the tip of the rod allows spectroscopic signals to pass through. The goal is to detect and analyze groundwater contaminants. This type of analysis presents major challenges because of the number of species present and the complex nature of the soil. 

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