A monolithic capsule phase microextraction method combined with HPLC-DAD for the monitoring of benzoyl urea insecticides in apple juice samples

Fruit juices may contain harmful residues of pesticides that are associated with ecological and health risks. Thus, it is critical to develop sensitive and accurate methods for the monitoring of pesticides in these food products. In the present study, a simple and sensitive capsule phase microextraction (CPME) protocol combined with high-performance liquid chromatography-diode array detection (HPLC-DAD) was developed for the monitoring of benzoyl urea pesticides (chlorfluazuron, diflubenzuron, hexaflumuron, lufenuron, and triflumuron) in apple juices. Among the different examined sorptive phases, monolithic sol-gel poly(caprolactone)-poly (dimethylsiloxane)-poly(caprolactone) capsules were found to exhibit the highest extraction efficiency. The adsorption and desorption steps of the CPME method were optimized and the proposed method was validated. Under optimum conditions, the limits of detection for all analytes were in the range 0.15-0.30 ng mL(-1). Moreover, the proposed protocol exhibited good linearity, accuracy, and precision. The relative recoveries of the method ranged between 90% and 108%, and the relative standard deviations were <8% and 9% for intra-day and inter-day precision, respectively. The ComplexGAPI index was used to evaluate the green potential of the proposed method. Finally, the proposed method was employed in the analysis of a wide variety of commercially available apple juice samples.

Automated summary

A simple and sensitive method for monitoring pesticide residues in apple juices was developed using capsule phase microextraction (CPME) combined with high-performance liquid chromatography-diode array detection (HPLC-DAD). The monolithic sol-gel poly(caprolactone)-poly(dimethylsiloxane)-poly(caprolactone) capsules showed the highest extraction efficiency among the different sorptive phases examined. The method exhibited good linearity, accuracy, and precision, with limits of detection ranging from 0.15 to 0.30 ng mL(-1).