DETERMINATION OF RARE-EARTH ELEMENTS BY INDUCTIVELY COUPLED PLASMA MASS-SPECTROMETRY WITH ION CHROMATOGRAPHY

Inductively coupled plasma mass spectrometry (ICPMS) has been used for analysis of trace rare-earth elements as impurities that exist in other rare-earth material. ICPMS attains the pg.mL-1 level detection in solution for all of the rare-earth elements by means of conventional introduction system. On the other hand, an interference problem due to polyatomic ions is well-known and is especially critical for determination of the rare-earth elements. In order to solve this problem, the ion chromatographic analyzer was combined with ICPMS. After separation from a main material by ion chromatography (IC), trace rare-earth elements were directly introduced to ICPMS and analyzed. The detection limits for 14 rare-earth elements were from 1 to 5 pg.mL-1 in solution and ng.g-1 in solid. The linear range was 10(6), from 10 pg.mL-1 to 10-mu-g.mL-1, and the repeatability was better than +/- 1% of the relative standard deviation (RSD) for Lu.