DETERMINATION OF NEUTRAL CHLORINATED EXTRACTABLE ORGANIC-COMPOUNDS IN WATER SAMPLES USING LARGE-VOLUME ON-COLUMN INJECTION CAPILLARY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

An automated large volume on-column injection technique (LOCI) for capillary gas chromatography - mass spectrometry, GC-MS, with solvent divert and heated retention gap technology has been used to simplify the method for determining sixteen neutral chlorinated extractable compounds (NCEC) in industrial plant process water samples at a level of 10 ng/L. According to the simplified procedure, 30 mL of water sample is extracted with 5 mL hexane, and 100 mu L of the extract analyzed by combining large volume on-column injection with mass-selective detection operated in the selected ion monitoring mode. This combination has enabled simplification of the sample preparation and analysis procedures and provided a fast, labor-saving technique for analyzing water samples. Simplifications include significant reduction of sample and eluent volumes during extraction, and elimination of the Kuderna-Danish evaporative concentration step. The latter simplification has not only resulted in significant time savings, both during the analysis and for subsequent glassware cleaning; analyte tosses and the introduction of contaminants and artifacts which may occur during this step have also been eliminated.