Determination Of Trace Impurity Elements In Three Materials Including Zirconium Alloy And Other Materials By Matrix Separation-ICP-MS

Inductively coupled plasma mass spectrometry(ICP-MS)is an inorganic mass spectrometry for simultaneous analysis of multiple elements,which has been widely used in metallurgical analysis.ICP-MS has such advantages as simple spectrogram and high sensitivity,but inevitably there are mass spectrum interference problems,which need to be solved by other auxiliary means.All isotopes are interfered by polyatomic ions or isobars of matrix element and coexistent elements when Cd in Zircaloy and other materials was determined by ICP-MS,which needs to be eliminated.A method for the determination of various trace impurity elements including Cd in Zircaloy,Ni-base superalloy and high purity molybdenum by inductively coupled plasma mass spectrometry(ICP-MS)was developed.Ion exchange was used to eliminate the matrix interference of Zr on Cd in analysis of Zircaloy by ICP-MS.At the same time,5 elements including Mg was separated and enriched simultaneously,which reduced the detection limit.The experimental conditions for separation of Cd and Zr were studied,including medium acidity,leaching acidity,elution acidity,sampling concentration and flow rate.The behavior of other impurity elements under the separation conditions obtained by an optimization experiment was also investigated.The separation period of the method is about 15 min,which has a fast analysis speed.Other impurity elements such as B were directly determined by internal standard method without separation.The detection limit for all the elements in the established method were 0.0058?0.21 ?g/g.The recoveries ranged from 85%to 110%,and RSD was less than 5%for each element.Aiming at eliminating the mass spectra interference in the determination of Cd and other elements in Ni-base superalloy by ICP-MS,two methods including precipitation with lead acetate as precipitant and ion exchange were adopted to separate the matrix.The conditions for the two separation methods were investigated and optimized.The experimental results demonstrate that the separation of Cd and Mo,the major element bring interference,could be achieved by all the two methods.The detection limits of the two methods in the determination of Cd are 0.14 ?g/g and 0.12 ?g/g,respectively.In contrast,the method of precipitation is simpler and more efficient for less separation period with 5 min and the capacity of separating 21 elements simultaneously.The detection limit for all the elements were 0.011?0.97 ?g/g.The recoveries ranged from 82%to 109%,and RSD was less than 5%for each element.Due to the mass spectra interference in the determination of Cd and other elements in high purity molybdenum by ICP-MS is similar to that of Ni-base superalloy,precipitation with lead acetate as precipitant could effectively separate 8 impurity elements including Cd from matrix element of high purity molybdenum,so as to eliminate the interference.The separation period of the method is about 5 min,and the detection limits for the 8 elements were 0.025?0.80 ?g/g.The recoveries ranged from 85%to 107%,and RSD was less than 5%for each element.The application range of ordinary quadrupole ICP-MS was further expanded by the research and establishment of the three methods above,which also solved the problem that the lower limit of determination of some elements in corresponding products cannot be reached,and better met the demand of actual detection with a fast analysis speed.