Research on the distribution of neonicotinoid and fipronil pollution in the Yangtze River by high-performance liquid chromatography

Abstract

Neonicotinoid and fipronil insecticides have been consumed worldwide, particularly in China. There is growing interest in the environmental research community about the occurrence, sources, and risks of neonicotinoids and fipronil. A new method based on high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and disc solid phase extraction (SPE) techniques were developed for the determination of neonicotinoids and fipronil in seawater in this research. The effects of the styrene divinyl benzene-reverse phase sulfonated (SDB-RPS) membrane-based solid phase extraction optimization process and the HPLC separation parameters on the detection results of the target compounds were studied. Under the optimized conditions, the detection limit of this method for 12 target compounds ranged from 0.05 ng L⁻¹ to 0.50 ng L⁻¹ and absolute recovery was achieved from 58.9–106.5%. The results proved that this method can effectively detect neonicotinoid and fipronil pesticides in seawater. At the same time, dinotefuran, nitenpyram, thiamethoxam, imidacloprid, thiacloprid, fipronil and its metabolites were found in seawater samples from the Yangtze River Estuary and the adjacent sea area. Among them, the total concentration of neonicotinoid insecticides ranged from ND-12.45 ng L⁻¹ and the average total concentration was 3.5 ng L⁻¹; the total concentration of fipronil and its metabolites ranged from ND-2.45 ng L⁻¹, and the average total concentration was 0.79 ng L⁻¹. The results showed that there was contamination of neonicotinoids and fipronil in the Yangtze River Estuary and its adjacent area.