A HILIC LC-MS/MS method for the determination of perchlorate and chlorate in coffee samples

Abstract

A liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the determination of chlorate and perchlorate in instant coffee and Ready-to-drink coffee (RTD coffee) with the usage of a trifunctional-groups modified hydrophilic interaction chromatography (HILIC) column. After the purification with MCX columns, the separation of sample extraction was completed on a Tour DEA column (100 mm × 2.1 mm) with a gradient program of 0.4 % aqueous ammonia–2 mmol/L ammonium acetate solution and acetonitrile as the mobile phases. In order to ensure the reliability and sensitivity of the method, the isotope internal standards and multiple reactions monitoring (MRM) model were applied in the quantification process. The satisfied data were obtained during the validation process, the linearity range for chlorate and perchlorate were 5.0 ∼ 1000 μg/L and 0.5 ∼ 100 μg/L, respectively. The recovery rates were 98.7 ∼ 115 % for chlorate and 92.3 ∼ 102 % for perchlorate in coffee samples with satisfied relative coefficients (<10 %). The method LOQs for chlorate and perchlorate were 5 μg/L and 0.5 μg/L, respectively. Finally, the risk assessment results of 94 coffee samples indicated that the consumption of instant coffee was relatively safe and concern should be paid to certain RTD coffee product.