Development of an effervescence‐assisted dispersive liquid phase microextraction using a binary solvent as a simultaneous extraction and preconcentration approach specialized for the analysis of pesticides in grape juice without dilution

In this study, a swift and economical extraction and preconcentration method called effervescence‐assisted dispersive liquid‐phase microextraction was developed to analyze the pesticide content of different grape juices. To propel the microextraction method, the sample was transferred to a conical bottom glass test tube, and ammonium chloride was added and vortexed to dissolve. Then, sodium bicarbonate and a mixture of 1,2‐dibromoethane and n‐hexane were added. The tube was located in a water bath and the produced carbon dioxide bubbles dispersed the extraction solvent into the sample. Finally, it was centrifuged and one microliter of the sedimented phase was injected into a gas chromatograph equipped with a flame ionization detector. Under the optimum conditions, the limits of detection and quantification ranged from 0.9 to 4.1 and 3.0 to 13.6 μg/L, respectively. Extraction recoveries and enrichment factors were achieved in the ranges of 36%–80% and 180%–404%, respectively. The inter‐ and intra‐day relative standard deviations were in the ranges of 3.4%–10.6% and 2.6%–9.7%, respectively. Also, the coefficients of determination in the calibration curves were ≥0.990. Short extraction time, no sorbent or costly apparatuses, using inexpensive chemicals, applying microliter levels of the extractant, and no dilution of the real samples are the highlights of the study.