Fenpropathrin [HRP]

This study focused on contamination levels and spatial distributions of four common pyrethroids found in agricultural soils of the Yangtze River Delta (YRD), China. Pyrethroids were detected in 241 soil samples (88.8% detection rate) with total concentrations ranging from cypermethrin (1.10 ng/g) > deltamethrin (0.89 ng/g) > cyhalothrin (0.20 ng/g). The highest concentration of fenpropathrin was recorded as 37.6 ng/g. The highest detection rate of 63.9% was found for cyhalothrin. A distinct pattern of spatial distribution was observed where high concentrations of pyrethroids were detected in sites around Taihu Lake. Potential sources of pyrethroids in agricultural soils from the YRD region include pyrethroids used for pest control and wastewater irrigation in the region. Redundancy and correlation analyses show that the soil TOC values have played a significant role in the behavior of pyrethroids in agricultural soils of the YRD region. Potential ecological risks of pyrethroids in agricultural soils of the YRD region are low. Cypermethrin and cyhalothrin showed potential toxic effects on the ecological conditions of agricultural soils in 4.6% and 2.9% of the sampling sites, respectively. Further studies should pay more attention to the potential human health risks posed by pyrethroids in agricultural soils for the protection of soil quality and food safety. (C) 2020 Elsevier B.V. All rights reserved.

A simple, green and efficient method for extraction, purification and enrichment of pesticide residues of triazoles and pyrethroids in Longan fruit was developed by ultrasonic-assisted aqueous two-phase extraction (UAATPE) coupled to vortex-assisted dispersive liquid-liquid microextraction (VADLLME). Using an aqueous two-phase system (ATPS) of ethanol/K2HPO4 as extraction solvent, the composition of the ATPS, extraction temperature and time were investigated, respectively. Then VADLLME process also was optimized by investigating type and volume of extracting and dispersive solvents, vortex-assisted time and salt addition. The optimum conditions were as follows: the ATPS composition of ethanol concentration 30.0% (w/w) and K2HPO4 concentration 25% (w/w), extraction temperature 70 degrees C and extraction time 15 min for UAATPE; 1-dodecanol 200 mu L as extraction solvent, ethanol 1.25 mL as dispersive solvent, vortex-assisted time 1.5 min and addition of NaCl 4% (w/v) for VADLLME. Ethanol as extraction solvent and dispersive solvent could directly connect UAATPE with VADLLME without extra steps. By means of HPLC-DAD detection, nine pesticides had good linearity ranged from 0.0200 to 13.59 mu g/mL (R-2 >= 0.9957). LODs and LOQs were in the range of 0.005576-0.01740 mu g/mL and 0.01859-0.05010 mu g/mL, respectively. UAATPE-VADLLME coupled to HPLC was successfully applied to simultaneous determination of multiple pesticides in Longan fruit, and mean recoveries and RSDs were between 76.95% and 98.63%, 1.2% and 9.8%, respectively. Furthermore, myclobutanil, fenpropathrin and deltamethrin were detected in pericarp and pulp of Longan samples from different districts, respectively. (C) 2020 Elsevier B.V. All rights reserved.