DETERMINATION OF S-TRIAZINE HERBICIDE RESIDUES IN URINE - STUDIES OF EXCRETION AND METABOLISM IN SWINE AS A MODEL TO HUMAN METABOLISM

The excretion and metabolism of atrazine and procyazine were studied in pigs. Pigs were used because of their close modeling of human metabolism. Young (3-5 months) Pittman-Moore miniature pigs were dosed under anesthesia via a stomach tube with 0.1 g of the commercial grade herbicide dissolved in ethanol. Urine samples were collected from a drain in the floor of the metabolic cages. The urine samples were extracted and subsequently analyzed by gas chromatograph using the Hall electrolytic conductivity detector in the nitrogen mode. A column clean-up procedure using deactivated alumina was employed to further purify the urine extracts for analysis using electron-capture or mass spectrometric detectors.Atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] and its metabolites were detected in the urine for slightly more than 24 h. Procyazine (2-[(4-chloro-6-cyclopropylamino)-s-triazin-2-yl)-amino]-2-methylpropionitrile) and its metabolites were not detected in the urine after about 10 h. Gas chromatographic/mass spectrometric analysis of pig urine extracts showed conclusively that the parent herbicide was being excreted. In addition, deethylatrazine [2-chloro-4-(amino)-6-(isopropylamino)-s-triazine] was identified as an atrazine metabolite, and several other compounds were identified as impurities in the dosing samples. If the findings of this research are extrapolated to monitoring studies in man, s-triazine herbicide may be expected in the urine within 24 h of exposure and primarily as the parent compound. © 1979, American Chemical Society. All rights reserved.