Determination of rare earth impurities in lanthanum-magnesium alloy by inductively coupled plasma mass spectrometry

After the sample was dissolved by nitric acid,a method for determination of rare earth impurities in lanthanum-magnesium alloy was established by inductively coupled plasma mass spectrometry.Appropriate isotopes and interfering elements correction equation were chosen to overcome spectral interferences.The instrument working conditions were optimized with power of 1 100 Wand carrier gas flow rate of 0.80L/min.A discussion of the impact of testing conditions on the result was conducted.The testing conditions were confirmed as follows:1%nitric acid as medium,Cs as internal standard element and substrate concentration less than 0.3mg/mL.The low limit of determination of the method was 0.006 9-0.046ng/mL.This method was employed to determine actual sample with recoveries of 98%-102%.Compared with inductively coupled plasma atomic emission spectrometry(ICP-AES),the results of both methods were basically consistent with each other,and relative standard deviation(RSD,n=6)were in the range of 1.7%-4.5%.