Enantioselective dissipation of pyriproxyfen in soil under fertilizers use

An enantioselective method of pyriproxyfen enantiomers in fertilized soil was established on Lux Cellulose-3 column using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The effects of urea, potassium dihydrogen phosphate, organic fertilizer and compound fertilizer on the dissipation of pyriproxyfen in soil were investigated. Studies have shown that pyriproxyfen had a good linearity in the range of 0.050-7.5 μg/g. The method LODs and LOQs of two enantiomers were 0.0032-0.015 μg/g and 0.050 μg/g, respectively. The recoveries of two enantiomers ranged from 80.61% to 110.86%, intra-day together with inter-day RSDs of 1.38-12.52%. The results indicated that compound fertilizer could promote the dissipation of pyriproxyfen in soil, while the organic fertilizer, potassium dihydrogen phosphate and urea slowed down the dissipation of pyriproxyfen. Enantioselective dissipation of pyriproxyfen enantiomers occurred in blank soil and fertilized soil but performed not obviously. Pyriproxyfen almost not dissipated for 42 d when urea was added. These results revealed that the use of fertilizers would have impacts on the behaviors of this pesticide. The impacts were relatively complex which should be fully considered in future environmental risk evaluation.