Determination Of Trace Elements Arsenic,Silver,Gallium,Cadmium,Yttrium And Tellurium In Nickel Base Superalloy By Inductively Coupled Plasma Mass Spectrometry

Six trace elements As,Ag,Ga,Cd,Y,Te in Nickel base superalloy were determined by inductively coupled plasma mass spectrometry(ICP-MS).The possible disturbances in the analysis were investigated systematically,including mass spectrum interference and non mass spectrum interference.By optimizing the parameters of the instrument,the best working parameters of the instrument were determined.The interference was corrected by kinetic energy discrimination(KED)technology.The appropriate isotopes were determined and different internal standard elements were selected for correction.A reasonable method was investigated by a process of trial and error,which corrected the serious interference of molybdenum oxide ion on the determination of cadmium.At last,six trace elements were verified by precision tests and standard addition recovery tests.The hydrochloric-nitric-hydrogen peroxide acid decomposition system was selected to digest samples.2 μg/L 193Ir or 6 μg/L 115In was used as the calibration internal standard of 75As,2 μg/L 103Rh as the calibration internal standard of 111Cd,89Y and 126Te,6 μg/L 187Re as the calibration internal standard of 71Ga,6μg/L 133Cs as the calibration internal standard of 107Ag.The best carrier gas flow rate was 1.10 L/min,the best RF power was 1 300W,and the integral residence time was 50ms.The kinetic energy discrimination model was selected to determine the sample solution,and the helium flow rate was 3.5 ml/min.It was shown experimentally that the interference from 95Mo16O+ peak produced by Mo in nickel base superalloy could be corrected well by the established mathematical correction,and the method must be written in the instrumental program before the determination of 111Cd.As the test result shown,the correlation coefficient of calibration curve of each element was over 0.999,and the linear correlations were good.The detection limits of trace elements as Ag,Ga,Cd,Y and Te in nickel base superalloy were 0.58,0.09,0.02,0.03,0.01 and 0.14 μg/L,respectively.The RSD was lower than 10%.The stability and sensitivity of the instrument were good,and the recovery rates of the method were 85%-110%The results were accurate and reliable.