Determination Of The Contents Of Gold, Silver, Copper, Palladium And Zinc In Gold Jewellery With Yttrium Or Indium As Internal Standard Element Using ICP Spectrometer Method

The new method is determined gold、silver、copper、paladium and zinc in gold jewellerywith yttrium or indium as the internal standard element using ICP Spectrometer Method. Atleast two accurately weighed samples are dissolved in aqua regia and made up to an exactlyweighed mass.Exactly weighed portion (aliquots) of those sample solutions are mixed withthe internal standard and made up to the measuring volume.Using an ICP emissionspectrometer,the elements content of the sample solution is measured by comparison of theratio intensities of the spectral emission of elements and Yttrium or Indium with the rationsfor solutions containing known masses of element and Yttrium,dtermination the content ofelements.The gold content of the alloys lies between585‰and917‰in the context.Compared tofire assay,the deviation of new method test results is0.7‰and the two times of standarddeviation is1.4‰at the confidence of95%,which fully verified the precision and accuracy ofthe ICP spectrometer method with Y or In as internal standard.Comparing to the fire assay method, it could be verify the reliability of this method, forfire assay method was the most classic method in the world. The test results indicated that theprecision and accuracy of this ICP method was worse than those of the fire assay method. Butit was a very advantage method to replace the traditional method with the Y or In as theinternal standard using the ICP spectrometer method. This ICP method could determine theother elements except the gold element with the highly precision and accuracy, which showedit was more power in the analysis area than the fire assay method, because it could determinethe alloys containing the such elements as Pd. and Rh,which could not be dissolved nitricacid.Comparing to the X ray fluorescence spectrometer method, it could be used to verify theaccuracy of the ICP method beside the gold,Thus, we could judge the ICP method morereliability than the X-ray fluorescence spectrometer method with the gold results of the fireassay method. The analysis results indicated the ICP method could get more highly precisionand accuracy,which could not be disturbed by the coating metal.This ICP method just need alittle sample.And it is a destroy method with the finished jewellery,which could not recoverthe original appearance and led to a little effect for the raw materials.