DETERMINATION OF TRIAZINE HERBICIDES AND METABOLITES BY SOLID PHASE EXTRACTION WITH HPLC ANALYSIS

An efficient solid phase extractive preconcentration/separation method was developed for the trace determination of herbicides in aqueous samples using Amberlite XAD-4 resin as the adsorbent. The retained herbicides were eluted with methanol at a flow rate of 1.0mLmin(-1) and determined by HPLC-DAD (wavelength of 220nm) using water (pH:4.7, phosphoric acid) and methanol (ratio 35:65) as the mobile phase with a flow rate of 1.0mLmin(-1). Quantitative recoveries of simazine, atrazine and its metabolities were achieved at optimized analysis conditions that included 0.75g of resin; a pH of 3.0; an eluent volume of 3.0mL; an eluent flow rate of 1.0mLmin(-1); and a sample flow rate of 4.0mLmin(-1). The limits of detection, preconcentration factor, and linear ranges for the herbicides were 0.084-0.121 mu gL(-1), 1000, and 0.5-20mgL(-1), respectively. The performance of the method was evaluated by analysis of spiked water samples. The recoveries of simazine, atrazine and their metabolities were found to be quantitative (99.6-104.8%) with RSDs of 2.2-4.8% and 2.8-4.7% for intra-day and inter-day precision, respectively. The proposed method was successfully applied for trace determination of studied analytes in waste water, apple juice, and red wine samples.