Abstract

Carbaryl and seven organophosphorous pesticides were analyzed simultaneously using on-line solid phase extraction (on-line SPE) coupled with liquid chromatography tandem mass spectrometry (LC/MS/MS). The target pesticides are Carbaryl, Methyl demeton, Fenitrothion, Malathion, Parathion, Phenthoate, Diazinon, and EPN. This method includes the direct injection of 500 μL in the water sample, a 15 min separation period using a rapid resolution liquid chromatography system with on-line SPE, and detection through electrospray ionization (ESI) positive mode. The percentage of recovery of all pesticides ranged from 85.3 % to 100 %. This method showed an accuracy of ≥ 90.0 %, possessing limits of detection and quantification within 0.05 to 0.28 μg/L and 0.16 to 0.89 μg/L, respectively. The correlation coefficients (r) for the calibration curves within a range of 0.5 to 8.0 μg/L were higher than 0.99. The evaluation results showed the efficacy of the method for all contents, and no pesticides were detected in the water quality sample.