Background Triazine herbicides are one kind of the most widely used herbicides in China. They are persistent, toxic, and bio-resistant in the environment, including chronic toxicity to aquatic organisms, accumulation in the ecosystem, and harm to human health.
Objective The methodological research is conducted to establish a method for determination of six triazine herbicides, including atrazine, fortrol, metolachlor, metribuzin, prometryn, and simazine, in water by solid phase extraction (SPE) coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS).
Methods The instrument conditions and pre-treatment conditions were optimized. Samples were applied to Waters Oasis HLB extraction cartridges, eluted with methanol, and dissolved in 90% methanol. Ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) in multiple reaction monitoring mode with electrospray ionization source by positive ion mode was used to select target ion pairs for determination. The external standard method was also used for quantitative determination. Four samples of Taihu Lake, three samples of source water, and ten samples of drinking water were detected by the established method.
Results All the six triazine herbicides had good linear relationships within the range of 0-250.0 μg·L-1, and the correlation coefficients were all greater than 0.999. The detection limits were 0.54-1.44 μg·L-1, the quantification limits were 1.8-4.8 μg·L-1, the average recovery rates were 75.0%-93.3%, and precision ranged from 0.6%-5.0%. Triazine herbicides were not detected in source water and drinking water. The concentration of metribuzin in water samples of a lake was 0.16-0.17 μg·L-1, and the other five analytes were not detected.
Conclusion The method is simple to operate, with a low detection limit and a high sensitivity, and can meet the requirements of simultaneous determination of selected six herbicide residues in lake water samples.
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