Determination of 2,4-dichlorophenoxyacetic acid in environmental and food samples using salt-assisted liquid-liquid extraction coupled with micro-channel and high-performance liquid chromatography

In this research, 2,4-dichlorophenoxyacetic was determined using a salt-assisted liquid-liquid extraction in a micro-channel. Firstly, the sample solution, extraction solvent, and salt were mixed with a magnet stirrer, and then the mixture was transferred into a micro-channel using a syringe pump. Affecting factors on the extraction efficiency of 2,4-dichlorophenoxyacetic such as extraction solvent and its volume, salt amount, pH of sample solution, micro-channel shape, length, and inside diameter were investigated and optimized. Under the optimized conditions, the detection limit of the proposed method was 0.051 mu g/ml, and its linear was in the range of 0.15-30.0 mu g/ml with an R-2 coefficient of 0.9927. To show the micro-channel effect on the efficiency of the proposed method, its extraction efficiency was compared with the conventional salt-assisted liquid-liquid extraction method. The results confirm the synergetic effect of micro-channel on the extraction efficiency of 2,4-dichiorophenoxyacetic. Finally, the proposed method was successfully applied to determine 2,4-dichlorophenoxyacetic in environmental and vegetable samples.