DETERMINATION OF POLAR PESTICIDES IN-GROUND WATER USING LIQUID-CHROMATOGRAPHY MASS-SPECTROMETRY WITH ATMOSPHERIC-PRESSURE CHEMICAL-IONIZATION

A method is described for determination of pesticides in ground water by liquid chromatography combined with mass spectrometry (LC-MS) using atmospheric pressure chemical ionization (APCI). The study demonstrat es the sensitivity of the technique, with detection limits for water s amples of about 0.001-0.005 mu g/l, corresponding to 50-300 pg injecte d. Performance data for the method such as recovery, precision and lin earity are also reported. It is illustrated that the technique is appl icable for many different types of pesticide structures, such as triaz ines, phenylurea herbicides, acetanilides, organophosphorus insecticid es, etc. Twelve different pesticides and pesticide degradation product s are included in the study. The optimization of inlet conditions with respect to sheath gas pressure, vaporizer temperature, capillary temp erature and corona current is reported. Applicability of the method fo r analysis of ''real-world'' ground water samples is demonstrated.