Determination of Cr£¨¢ó£© and Ultratrace Cr£¨¢ö£© in Toy Materials by Co-precipitation Assisted Separation-Ion Chromatography-Inductively Coupled Plasma Mass Spectrometry

KeyWord:toys  Cr£¨¢ö£©  Cr£¨¢ó£©  co precipitation  IC  ICP-MS  speciation analysis

Abstract:

      The sample was extracted with 0ª±07 mol/L hydrochloric acid.Migratable chromium in the extract was determined by inductively coupled plasma mass spectrometry£¨ICP-MS£©.Some other extract was taken and the high content of interferential positive ions was removed by co-precipitation method with aluminium nitrate.Then Cr£¨¢ö£© in the extract was determined by ion chromatography-inductively coupled plasma mass spectrometry£¨IC-ICP-MS£©.Cr£¨¢ó£© content was obtained by minusing Cr£¨¢ö£© content from the total migratable chromium content £¨Cr£¨Total£©£©.The method quantitation limit for Cr£¨Total£© and Cr£¨¢ö£© reached to 0.01 mg/kg and 0.003 mg/kg,respectively.The method was then validated by conducting standard-addition experiments to the difference categories of toy materials according to Toy Safety Directive 2009/48/EC.The recoveries of Cr£¨Total£© and Cr£¨¢ö£© from the standard-addition experiments were in the ranges of 90.2%-101.5% and 96.7%-106ª±7%,respectively, and the inter laboratory relative standard deviations were less than 7.4% and 7.9%,respectively.Therefore,the method was concluded to be accurate and reliable,which could satisfy the requirements of Cr£¨¢ó£© and Cr£¨¢ö£© in 3 categories of toy materials of Toy Safety Directive.