Enhancing the quantification accuracy for selected endocrine disruptors in different tea samples by GC-MS using matrix matching calibration strategy

Abstract

This study was focused on enhancing the accuracy of quantifying twelve endocrine disruptors in green and black tea samples. The analytes included seven pesticides, two hormones, and three phenolic compounds. An optimized dispersive liquid-liquid microextraction method was used to preconcentrate the analytes from the tea samples for determination by gas chromatography-mass spectrometry. The matrix of the tea samples caused an enhancement effect on the extraction method and this yielded percent recoveries higher than 180% when calculated using the external calibration method. Matrix dilution and matrix matching calibration were used to prevent the formation of tea particle layers and enhance quantification accuracy, respectively. Similar tea matrices were used to prepare calibration standards and these were used to quantify the spiked analytes. The percent recovery results calculated for the analytes using matrix matching ranged between 92 and 105%. Both repeatability and reproducibility precision tests produced percent relative standard deviations below 10%.