| Three analytical methods for the separation and determination of chromium (III), chromium (VI), iodate (IO3-), iodide (I) and bromate (BrO3-), bromide (Br-) using ion chromatography with inductively coupled plasma mass spectrometric detection (IC-ICP-MS) was developed. Dionex IonPac-AG 14 A (Dionex, USA) or IonPac-AS 14 A (Dionex, USA) as separation column. A mobile phase consisting of 60 mmolL-1 HNO3 was used to separate and determination the mixture of the chromium (Cr) species including Cr3+ and CrO4-. A mobile phase consisting of 5 mmolL-1 sodium thiosulfate was used to separate the mixture of the bromine (Br) species including BrO3- and Br-. And a mobile phase consisting of 30 mmolL-1 sodium thiosulfate was used to separate the mixture of the iodine (I) species including IO3- and I". Subsequently, eluates from a separation column were directly introduced into ICP-MS and detected at rn/z 50, 52, .53, 54 for chromium species, 78.9, 80.9 for bromine (Br) species and 126.9 for iodine species. Separation parameters were optimized. IO3-, I" and Cr (III), Cr (VI) were completely separated within 2 min. BrO3- and Br" were completely separated within 9 min. Detection limits (S/N = 3) for Cr (III) and Cr (VI) were 0.05 μgL-1 and 0.5 μgL-1. The linearrange was 4 orders of magnitude, from 0.05 jAgL"1 to 500 [xgL"1. With regard to reproducibility, R.S.D. (n = 7) was less than 4%. Detection limits (S/N = 3) for BrO3" and Br" were 1.0 ugL1 and 0.8 ^gL"1. The linear range was 3 orders of magnitude from 1.0 ugL^to 500 \igIS1. With regard to reproducibility, R.S.D. (n = 7) was better than 3%. Detection limits (S/N = 3) for IO3' and I" were 0.5 [XgL1 and 1.0 jxgL"1. The linear range was 3 orders of magnitude from 0.5 [igL"1 to 500 UgL"1. With regard to reproducibility, R.S.D. (n = 6) was less than 4%. The methods were applied to the analysis of IO3', I" and Cr (III), Cr (VI) in water, urine, and vegetable samples. |
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