DEUTERATED INTERNAL STANDARDS FOR GAS-CHROMATOGRAPHIC MASS-SPECTROMETRIC ANALYSIS OF POLAR ORGANOPHOSPHORUS PESTICIDES IN WATER SAMPLES

It is essential to know whether drinking water contains any pesticides up to concentrations close to the European Union limit of 0.1 mu g/l, in order to protect the population. Mass spectrometry (MS) using a su itable internal standard (I.S.) should improve the quantitative analys is of pesticides, the I.S, circumventing loss of compounds during the analytical procedure and correcting the analytical variability. In thi s study we verified this assumption in GC-MS, synthesising specific in ternal standards for four organophosphorus pesticides with poor stabil ity, comparing the performances with and without the I.S. (C) 1998 Els evier Science B.V. All rights reserved.