pH-responsive deep eutectic solvents applied in the extraction of abamectin and endosulfan from water and fruit juice samples: A comparative study

A liquid–liquid microextraction assisted by switchable deep eutectic solvents (DESs) was applied for the extraction of abamectin and endosulfan. Three different DESs were synthesized using l-menthol, ethylene glycol, (1S)-(+)-camphor-10-sulfonic acid, and salicylic acid. The phase transition behavior of the DESs prepared was assessed by changing the pH of the solution. Among the prepared DESs, l-menthol: (1S)-(+)-camphor-10-sulfonic acid (5:1) provided the highest extraction yield of the analytes and was subjected to the liquid–liquid microextraction of abamectin and endosulfan. The central composite design was used to investigate the significance of critical variables on the extraction yield of the analytes of interest. The maximum extraction yield of analytes was achieved using 60 µL of DES, 80 µL of KOH (6 M), and pH of 6. The analytical performance of the method showed linearity over the concentration of 3–300 µg/L with the limits of detection varied from 1.0 µg/L to 1.5 µg/L for endosulfan and abamectin, respectively. The potential of the best DES in the extraction of abamectin and endosulfan from water and fruit juice samples was then examined under optimal extraction conditions.