Various extraction methods for detection of bistrifluron residues in Asian pear using high-performance liquid chromatography: application to dissipation patterns under open-field conditions

The present study was carried out to develop an analytical method for the detection and quantification of bistrifluron, a benzoylphenylurea compound, in pear using high-performance liquid chromatography with UV detection. Samples were extracted using conventional, AOAC and EN quick, easy, cheap, effective, rugged and safe QuEChERS' methods. As expected, conventional and EN-QuEChERS methods gave higher recoveries than AOAC. In addition, interference around the analyte retention time was observed in the conventional method. Thus, the EN-QuEChERS method was selected and validated by studying various parameters, including linearity, limit of detection, limit of quantification (LOQ), recovery and precision. Linearity was excellent, with a correlation coefficient of 0.9998. Recovery rates at three spiking levels (0.05, 0.2 and 1mg/kg) ranged from 73.76 to 98.66%. Intra- and inter-day precisions, expressed as relative standard deviations, were <6%. The LOQ of 0.05mg/kg was considerably lower than the maximum residue limit (1mg/kg) set by the Korean Ministry of Food and Drug Safety. The developed method was successfully applied to open-field pear samples, in which the target analyte was slowly dissipated (55% decline) over 14days with a half-life of 10.19days. Notably, the residue levels throughout the period of sample collection (14days) were lower than the maximum residue limit, indicating that the residue was not hazardous for consumers. Copyright (c) 2016 John Wiley & Sons, Ltd.