Determination of trichlorophenols in water samples by online pre-concentration method based on headspace in-tube microextraction-capillary electrophoresis

Abstract

In this study, a simple and efficient online preconcentration method based on headspace in-tube microextraction was used to simultaneously extract and preconcentrate small amounts of six trichlorophenols in aqueous samples. After extraction, the analytes were quantified by capillary electrophoresis and using the calibration curve of standard solutions. The effect of effective factors on the extraction process such as the pH of the donor phase, the type of the acceptor phase, the temperature and time of extraction, and the addition of organic solvent to the donor phase were investigated and optimized. Under optimal conditions, the linear dynamic range for the proposed technique was 15 to 1000 nM with a correlation coefficient of 0.99, and relative standard deviations were obtained with seven repetitions of the experiment and a concentration of 500 nM of analytes in the range of 4.78-7.63%. The detection limit of the method was 5-6 nM. The preconcentration factor for six trichlorophenols was obtained in the range of 310 to 661 times. Finally, this method was used to preconcentrate and measure six trichlorophenols in environmental water samples. The relative recoveries for the spiked samples were within the 82-92% range, indicating good accuracies and the absence of matrix effects.

Keywords

• headspace in-tube microextraction
• trichlorophenol
• online pre-concentration
• capillary electrophoresis