Determination of chlorinated acid herbicides and related compounds in water by capillary electrophoresis-electrospray negative ion mass spectrometry

Capillary electrophoresis electrospray negative ion mass spectrometry was investigated for the determination of chlorinated acid herbicides and several phenols in water. Sixteen analytes were separated as their anions in less than 40 min with a buffer consisting of 5 mM ammonium acetate in isopropanol-water (40:60, v/v) at pH 10. A sample stacking technique was used to provide lower detection limits and a fortified drinking water sample was made pH 10 and analyzed without further processing. Quantitative analyses with an internal standard gave recoveries in the 91-124% range and replicate measurements of a calibration standard gave relative standard deviations in the range of 3-10%. (C) 1998 Elsevier Science B.V. All rights reserved.