Abstract:

On the basis of environmental quality standards for surface water, a sensitive and simple method was developed for the simultaneous determination of 13 organic pollutants, including dimethoate, dichlorvos, trichlorfon, parathion, methyl parathion, malathion, demeton, acrylamide, aniline, benzidine, carbaryl, Microcystin-LR and atrazine in water samples by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) combined with direct injection. The water samples were filtered through 0.22 μm of microfiltration membrane. With methanol-0.01% formic acid as mobile phase, the separation was performed on a Kromasil 100-5 C18 column (150 mm×2.1 mm, 5 μm) in gradient elution. The flow rate was 0.5 mL/min. The column temperature was 40 ℃. The samples were detected by multiple reaction monitoring (MRM) mode with positive electro spray ionization. The organic pollutants were quantified by external standard method. The calibration curves of the organic pollutants show good linearity in suitable ranges with correlation coefficients (r) over 0.9995. The detection limits of organic pollutants in samples ranged from 0.02 μg/L to 0.1 μg/L. The relative standard deviations of organic pollutants were 0.5%-5.0% (n=6). The average recoveries of the 13 organic pollutants spiked in water samples ranged from 81.2% to 112%. The method has been proven to be sensitive, rapid and with little interference. It is suitable for the determination of the 13 organic pollutants simultaneously in the surface and underground waters.

Key words: direct injection, high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), organic pollutants, water samples