Determination of Impurity Elements in the Positive Electrode Material LiMn2O4 by Inductively Coupled Plasma Mass Spectrometry

Samples of LiMn2O4 were digested by microwave digestion, and impurity elements amounts of Na, Mg, Al, K, Ca, Ti, Cr, Fe, Cu, Zn, As, Ag, Cd and Pb in sample solutions were determined by inductively coupled plasma mass spectrometry (ICP-MS). Sample preparation was achieved by digestion with HNO3+HCl in a closed-vessel microwave system. The effects of mass spectrum interference were studied. Sc, Rh and Tl as internal standard elements were used to compensate matrix effect and signal drift. Under the optimal conditions, the detection limits of the 14 elements are in the range of 0.007 similar to 0.209 mu g . L-1. The recovery was 92.66%similar to 108.34% by adding standard recovery experiment, and the relative standard deviation (RSD) was less than 4.80% for all the elements. This method was simple, sensitive and precise, which could satisfy the sample examination request and provide scientific rationale for determining impurity elements of LiMn2O4.