Determination of 2,4-Dichlorophenoxyacetic Acid in Water and Edible Seeds Samples Using Salt-Assisted Liquid-Liquid Extraction Coupled with High-Performance Liquid Chromatography

Abstract

A simple, fast, and effective salt-assisted liquid-liquid extraction (SALLE) technique coupled with high-performance liquid chromatography (HPLC) was developed for determination of 2,4-dichlorophenoxyacetic acid (2,4-D) in water and edible seeds samples. Due to the polar nature of the 2,4-D molecules, LC analysis was performed on a CN stationary phase by using acetonitrile and acidic water as mobile phase. Extraction was achieved based on salting-out phenomenon. Affecting variables on the extraction efficiency of the 2,4-D, such as the solvent type and its volume, type of salt and its concentration, vortex time, and sample pH, have been investigated and optimized. The target analyte was successfully extracted by acetonitrile and sodium chloride as extracting solvent and salting-out agent, respectively. Under the optimized experimental conditions, calibration curve shows good linearity (r2 > 0.9957) and precision (RSD < 6.5%) in the concentration ranges of 1.0–10,000 ng/mL. The limit of detection (LOD) and limit of quantification (LOQ) were 0.3 and 1.0 ng/mL, respectively. The recoveries were in the range of 82.0–95.0 % with RSD values less than 7.2%. The method was successfully applied for the extraction and determination of 2,4-D in several edible seeds and water samples.