DETERMINATION OF THIAZOPYR RESIDUES IN SOIL AND PLANTS BY GAS-CHROMATOGRAPHY WITH NITROGEN-PHOSPHORUS DETECTION AND CONFIRMATION BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

Thiazopyr residues have been determined in soil, grass weeds and seedl ings of woody plants by gas chromatography. The herbicide was extracte d from soil and plant samples with ethyl acetate and plant extracts we re cleaned-up on a Florisil column. Thiazopyr levels were determined b y gas chromatography with nitrogen-phosphorus detection and confirmed by gas chromatography with mass spectrometry, ion trap detection. The average recoveries were always higher than 97% with a relative standar d deviation between 1 and 6%. The limit of detection for the herbicide was, at least, 0.01 mu g/g in soil and 0.02 mu g/g in plant with both gas chromatographic methods. Samples of soil and Pinus pinea L. plant s, treated with thiazopyr, were also analyzed. (C) 1997 Elsevier Scien ce B.V.