Ultra-performance liquid chromatography/tandem mass spectrometry for the trace-level identification of perchlorate in filtered drinking water treated with ozonation and chlorination disinfection processes

Abstract

ObjectivesIn the present study, a rapid, sensitive and selective method has been optimized for the quantification of perchlorate (ClO4−) in drinking water treated with ozonation and chlorination disinfection processes. MethodsAn analytical technique based on ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) has been optimized for the determination of perchlorate in drinking water. Prior to the analysis, the filtered water samples were directly injected into the system without any sample pretreatment. The ClO4− was quantified by examining the high intensity ion signal (m/z 83), produced by a removal of an oxygen atom from the ClO4− parent ion. ResultsThe performance of the method was established, achieving excellent values for instance linearity (R2 = 0.9999), limit of detection (0.009 µg/L), limit of quantification (0.030 µg/L), precisions (run-to-run, 1.56% and day-to-day, 2.15%) in terms of relative standard deviation while examining a standard of ClO4− (5 µg/L). The elution time of ClO4− was found to be 0.51 min at 300 µL/min flow rate. A total of forty-five water samples were studied, obtaining the ClO4− concentrations in bottled and metropolitan water ranging from 0.78 to 53.23 µg/L and 0.18 to 2.62 µg/L, respectively. ConclusionsThe metropolitan water was found to be least contaminated than the bottled water, and found to be lower than the Reference Dose (RfD) value 0.007 mg/kg body weight/day and Drinking Water Equivalent Level (DWEL) value 25 µg/L set by the Environmental Protection Agency (EPA). Furthermore, in comparison to the traditional methods, the proposed technique was found to be very efficient, cost-effective and rapid for the routine determination of ClO4− at trace level in water samples.