Simultaneous Determination of Paraquat and Diquat in Environmental Water Samples by HPLC-MS/MS

摘要

Purpose: To develop and evaluate a high throughput quantitative method for paraquat and diquat pesticide residues in environmental water samples using high pressure liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Methods: Environmental water samples were filtered, spiked with internal standards and injected directly for LC-MS/MS analysis. Chromatographic separation was achieved on a prototype column featuring reversed-phase, weak anion exchange and weak cationexchange retention mechanisms. A Thermo Scientific TSQ Quantum Access MAX triple stage quadrupolewas operated in selected reaction monitoring (SRM) mode to provide sensitive and selective detection. Results: Paraquatand diquat were sufficiently retained and completely separated on this prototype column within 5 minutes. Accurate quantitation was achieved through 3 orders of magnitude from 0.1 ng/mL to 100 ng/mL with a coefficient of determination (r2) greater than 0.999. Excellent precision was achieved with %RSD < 10% at 0.5 ng/mL and %RSD < 4% at 50 ng/mL..