Salting-out Assisted Liquid-Liquid Extraction for the Determination of Multiresidue Pesticides in Alcoholic Beverages by High Performance Liquid Chromatography

Abstract

A salting-out assisted liquid-liquid extraction (SALLE) method followed by high-performance liquid chromatography with ultraviolet-visible detector (HPLC-UV/Vis) has been proposed for determination of five multiclass pesticides residues including, atrazine, ametryn, terbutryn, carbaryl and chlorothalonil from various alcoholic beverages: beer, wine and Ethiopian honey wine (Tej). Experimental parameters influencing the extraction efficiency of the method such as the type and concentration of salt, volume of acetonitrile (the extraction solvent) and pH of the sample were assayed and the optimum conditions were established. Under the optimum experimental conditions, matrix-matched calibration curves were constructed using beer sample as the representative matrix and good linearity over wide concentration ranges were obtained with coefficient of determination (r 2 ) of 0.997 or better. The limits of detection (LOD) and quantification (LOQ) of the method, which were determined as 3 and 10 times a signal-to-noise ratio (S/N), were in the ranges of 1.3-3.9 and 4.5–12.8 µg L -1 , respectively. Precisions studied in terms of repeatability and intermediate precision (with-in lab reproducibility) at two concentration levels have demonstrated acceptable %RSD values, which were less than 10% in both cases. The applicability of the method was also investigated by analyzing various alcoholic beverages and demonstrated satisfactory recoveries in the ranges of 71-104% with their corresponding %RSDs less than 10% in all cases. The results of the study revealed that the developed SALLE method is selective and efficient sample preparation procedure prior to quantitative analysis of the target analytes by HPLC-UV/Vis.