Submitted to: Symposium on the Fate and Chemistry of Modern Pesticides Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/30/2001
Publication Date: N/A
Technical Abstract: Gas chromatography-ion trap MS/MS(GC-MS/MS) and high performance liquid chromatography-MS/MS (HPLC-MS/MS) were used to analyze for atrazine and its dealkylated and hydroxylated metabolites in 4 different forage grasses. For GC analysis, atrazine (ATR) and its dealkylated metabolites [deethylatrazine (DEA); deisopropylatrazine (DIA)] were extracted by methanol and cleaned up by liquid/liquid chloroform extraction followed by C18 solid phase extraction (SPE). The MS/MS ion trap condition was optimized by the Automated Methods Development Package (AMD). For the analysis of hydroxylated metabolites [hydroxyatrazine (HA); deethylhydroxyatrazine (DEHA); deisopropylhydroxy-atrazine (DIHA)] by HPLC- MS/MS, the samples were extracted by methanol and cleaned up by anion exchange (SAX) SPE followed by cation exchange (SCX) SPE. The selectivity and specificity of the MS-MS reduces background noise dramatically and provides sub-ppb detection limits. The average recoveries of the developed methods ranged from 94.3% to 113.1%, and the RSD values ranged from 6.5% to 22.1% for ATR, DEA, and DIA. The estimated limits of detection (LOD) were 0.6 ppb (ug/kg) for ATR, 1.3 ppb for DEA, and 0.3 ppb for DIA, respectively. For the hydroxylated metaobolites, the estimated LODs were 0.4 ppb for HA, 0.8 ppb for DEHA, and 3 ppb for DIHA. This method can be used to determine the fate of atrazine within plants and to evaluate their detoxification capacity.