Analytical method for the determination of atrazine and its dealkylated chlorotriazine metabolites in water using gas chromatography/mass selective detection

A multiresidue method is reported for the determination of atrazine and its dealkylated chlorotriazine metabolites in water. Water samples are buffere d to pH 10 and partitioned in ethyl acetate. Final analysis is accomplished using gas chromatography/mass selective detection (GC/MSD) in the selected ion monitoring (SIM) mode. The limit of detection (LOD) is 0.050 ng and th e limit of quantification (LOQ) is 0.10 ppb for 2-chloro-4-(ethylamino)-6-( isopropylamino)-s-triazine (atrazine), 2-amino-4-chloro-6-( isopropylamino) -s-triazine (G-30033), 2-amino-4-chloro-6-(ethylamino)-s-triazine (G-28279 ), and 2,4-diamino-6-chloro-s-triazine (G-28273). The mean procedural recov eries were 90, 92, 98, and 85% and the standard deviations were 12, 13, 16, and 20% for atrazine, G-30033, G-28279, and G-28273, respectively (n = 30) . The study was conducted under U.S. EPA FIFRA Good Laboratory Practice Gui delines 40 CFR 160 for method validation. The reported procedure accounts f or residues of G-28273 in water that are not included in EPA Method 507.