Hydrophobic deep eutectic solvent-based ultrasonic-assisted dispersive liquid-liquid microextraction for preconcentration and determination of trace cadmium and arsenic in wine samples

In present study, DL-lactic acid/trioctylmethylammonium chloride-based deep eutectic solvent (DES), which was considered as an environmental friendly extraction solvent to replace traditional organic reagent, was firstly presented for monitoring of trace cadmium (Cd) and arsenic (As) in wine samples by ultrasonic-assisted dispersive liquid-liquid microextraction (UA-DLLME) method. Moreover, different extraction conditions, including the type and volume of DES and dispersive solvent, pH of the solution, salt amount, time of vortex and sonication, were systematically evaluated. At the optimized extraction conditions, good linear relationships (0.50?8.0 ?g?L-1 for Cd, 2.0?50 ?g?L-1 for As) were obtained and limits of detection of Cd and As were 0.080 and 0.30 ?g?L-1, respectively. In addition, the accuracy (as recoveries %), and intra-/inter-day precision (as relative standard deviation %) were in the ranges of 90.6?103.6% and 2.9?4.5%, respectively. Finally, the proposed method was applied to analyze 6 kinds of wine samples, which possessed wide practical application value in monitoring heavy metal residues in wine and even complex food matrices.

Automated summary

In this study, a deep eutectic solvent (DES) based on DL-lactic acid and trioctylmethylammonium chloride was used with ultrasonic-assisted dispersive liquid-liquid microextraction (UA-DLLME) for monitoring trace levels of Cd and As in wine samples. The method showed good linear relationships, low detection limits, and reliable accuracy and precision, providing practical value for analyzing heavy metal residues in wine and complex food matrices.