Determination of Hexavalent Chromium in Drinking Water by High Performance Liquid Chromatography-Mass Spectrometry

A method for the determination of hexavalent chromium in drinking water by high performance liquid chromatography-electron-spray mass spectrometry was established.Sample was filtrated by a 0.45 μm micropore filter before injection.The separation of Cr(Ⅵ) was performed on a XterraTM MS C18 column using acetonitrile-1.5 mmol/L tetrabutyl ammonium hydroxide solution as mobile phase,and the detection of Cr(Ⅵ) was carried out under selected ion monitoring(SIM) mode with monitoring ions of m/z 118,117,101,85 and quantative ion of 117.The calibration curve of Cr(Ⅵ) was linear in the range of 1.0-100.0 μg/L with a quantitation limit of 1 μg/L.The avarge recoveries(n=5) of Cr(Ⅵ) from blank samples spiked with three levels of 1.0,2.0,10.0 μg/L were 91%,94%,97%,respectively,and the corresponding relative standard deviation were 12.2%,7.4%,3.5%,respectively.42 drinking water samples were used to test,and Cr(Ⅵ)was detected in 17 samples with the concentration of 1.2-15.4 μg/L.