Determination of s-triazine herbicides in Manitoba soils
Hill, Bernard Dale.
Atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine), cyanazine (2-[4-chloro-6-ethylamino-s-triazin-2-yl)amino]-2-methylpropionitrile), and cyprazine (2-chloro-4-cyclopropylamino-6-isopropylamino-s-triazine) were ultrasonically extracted form soils with aqueous methanol. Cleanup consisted of chloroform partitioning and column chromatography on deactivated basic alumina. Extracts were determined by gas chromatography with alkali flame ionization detection. The recoveries of bound a-triazine residues from soils fortified at 1 ppm ranged from 81.6 to 94.5%. Two 15 minute ultrasonic extractions were comparable to 24 hours of Soxhlet extraction for atrazine. Sensitivity is placed at 2 ng of s-triazine in the injected sample and the least determinable concentration is estimated at 0.02 ppm s-triazine in soil. The method developed is thought to be applicable to weathered s-triazine residues in field soils. The identity of the gas chromatographic peaks observed for atrazine, cyanazine, and cyprazine standards was confirmed using infrared spectrophotometry and mass spectrometry. Spectra obtained from 10-25 ug of trapped eluates are presented and interpreted. Although mass spectrometry was preferred, both confirmatory techniques could be used to identify these s-triazines in "unknown" extracted samples.