Simultaneous determination of chlorate and perchlorate in drinking water and foods using ultra performance liquid chromatography - tandem mass spectrometry

Abstract

Abstract A method was developed for the determination of chlorate and perchlorate in drinking water and 16 categories of foods by liquid chromatography coupled to a triple quadrupole mass spectrometry (LC-QqQ-MS/MS) with internal standard. The methods of chromatography (mobile phase, chromatographic column, injection volume) and pretreatment (extracting solution, purification cartridge) were improved and validated. After extraction, centrifugation and purification, chlorate and perchlorate were separated on the Torus DEA by gradient elution. The eluent was scanned in negative electrospray ionization mode. The data were acquired by multi-reaction monitoring. The oxygen-18 was added to all samples prior to extraction. The limit of quantification (LOQs) for chlorate and perchlorate were 0.20 µg/L and 0.05 µg/L in drinking water. The recoveries of chlorate and perchlorate were 96.5-109% and 99.3-111%, and intra and inter-day precision values ≤ 5% were obtained in drinking water. The LOQs for chlorate and perchlorate were 6.0 µg/kg and 1.0 µg/kg in fresh food. The LOQs for chlorate and perchlorate were 18.0 µg/kg and 3.0 µg/kg in dry food. For chlorate and perchlorate, the recoveries at three levels were 86.5-103% and 91.3-111%, the RSD (n=6) were 2.53-7.41% and 2.68-7.96% in foods. The 18 samples of drinking water were analysed, the concentration of chlorate and perchlorate was much lower than the limit of WHO drinking water. A total of 583 food samples were analyzed, the concentration of chlorate and perchlorate were ND-2.48 mg/kg and ND-4.55 mg/kg.