Analysis of Six Arsenic Speciations in Urine by High Performance Liquid Chromatography£­Inductively Coupled Plasma Mass Spectrometry

KeyWord:urine  arsenic speciation  high performance liquid chromatography£­inductively coupled plasma mass spectrometry

Abstract:

      A high performance liquid chromatography£­inductively coupled plasma mass spectrometry£¨HPLC£­ICP£­MS£© was developed for the analysis of six arsenic speciations£¬i.e£®arsenic betaine£¨AsB£©£¬dimethyl arsenic£¨DMA£©£¬arsenic choline£¨AsC£©£¬arsenite£¨As£¨¢ó£©£©£¬monomethyl arsenic£¨MMA£© and arsenate£¨As£¨V£©£© in human urine£®After the samples were diluted with water£¬the arsenic speciations were separated on a Dionex IonPac As7 anion exchange column by gradient elution£¬with 20 mmol/L ammonium carbonate£¨2% methanol£© and 100 mmol/L ammonium carbonate£¨2% methanol£© as the mobile phase£¬and finally analyzed by HPLC£­ICP£­MS£®The results indicated that the linear ranges for six arsenic speciations were all between 0 ¦Ìg/L and 100 ¦Ìg/L£¬with their correlation coefficients£¨r£© more than 0.999£®The detection limits were between 0.05 ¦Ìg/L and 0.15 ¦Ìg/L£®The reproducibility of this method was evaluated by precision under different concentrations£¬with relative standard deviations£¨RSDs£© less than 5.0%£®The recoveries for six arsenic speciations at three spiked levels ranged from 91.8% to 108%£®The evaluation results for five arsenic speciations in the standard reference material£­Arsenic Species in Frozen Human Urine£¨NIST SRM 3669£© were all within the range of standard values£®This method was sensitive£¬rapid£¬reproducible and accurate£¬and it was suitable for rapid determination of arsenic speciations in human urine£®The arsenic species in human urine were also characterized after food consumption£®It was revealed that different metabolic transformations occurred in human body after different foods containing arsenic were consumed.