Novel Microwave-Assisted Cloud Point Extraction Prior to Gas Chromatography–Mass Spectrometry for the Extraction of Organochlorine and Organophosphorus Pesticides from Fruit Juices

The current research aims to develop a simple, sensitive, and green analytical method for the group extraction/monitoring of 19 organochlorine and organophosphorus pesticides from fruit juices using microwave radiation to assist a cloud point extraction (MW-CPE) in combination with re-extraction in hexane and GC-MS/MS detection. The main experimental factors affecting the CPE and re-extraction have been optimized. The matrix-matched calibration was performed, and the limit of quantification (LOQ) for all studied pesticides at optimized conditions ranged between 5 and 47 ng L⁻¹. When applying only 0.25 mL of hexane for re-extraction, the proposed method shows good accuracy and precision. The “greenness” of the developed MW-CPE-GC-MS/MS method was assessed using the AGREE prep software. The method has been successfully implemented in pesticide analysis in commercially available fruit juices (lemon concentrate and red apple juice). The recovery values obtained for most analytes were within the range of 71% and 114% and RSD below 20% (exept Heptahlor, Aldrin, o,p-DDD, p,p-DDD and o,p-DDT, p,p-DDT). The developed method combines a preconcentration with a sample clean-up step due to the extraction of the pigments into the non-polar micelles during the extraction step, and deposition in the intermediate layer of MgSO₄ during the re-extraction step.