Screening of polar pesticides in groundwater in Hebei Province, China

As a big agricultural country，China has a relatively high pesticide usage in unit area , which is three times higher than developed countries. About 80% of pesticides directly enter the soil and the water through leaching or surface runoff during the usage of pesticides. In particular, some of the polar compounds are easier to migrate than other compounds, causing pollution of surface water and groundwater. The groundwater samples in Hebei Province, a major agriculture province in China, were screened by multi-residue liquid chromatography-tandem mass spectrometry for two consecutive years in 2014 and 2015. The results showed that among 44 polar compounds, 27 pesticides were detected in 2014 and 19 in 2015. Atrazine-desethyl-desisopropyl, 2,4-D and fomesafen were 434.3 ng/L, 711.5 ng/L and 508.2 ng/L respectively, which were significantly higher than those in other provinces in China. Atrazine and its metabolites were detected in both years. Except for Atrazine-desethyl-desisopropyl, other components were detected in high concentration in 2014. The detected concentrations of bentazone, hexaconazole, triadimenol, and triazolone were similar in the two years. Pesticides such as methomyl, isopropyl, diniconazole and imazethapyr were detected in 2014, but not in 2015, which is presumably related to the actual use of pesticides.