Highly sensitive determination of trace rare-earth elements in ultra pure rare-earth compounds by combining ICP-MS with HPLC and electrothermal vaporization

It is very difficult to accurately quantify trace rare-earth elements (REE) in ultra-pure rare-earth compounds by a single analysis method, such as ICP-AES, ICP-MS or electrothermal vaporization (ETV)/ICP-MS. We have developed a highly sensitive and efficient method by coupling the advantages of HPLC, ETV and ICP-MS. HPLC eliminated problems caused by matrix and severe overlapping of oxides and hydroxides peaks coming from the main component observed in ICP-MS. ETV greatly reduced the interference from additives contained in the eluent of HPLC, and provided an efficient introduction method for ICP-MS. The detection limits of other REE in pure Gd2O3 were 0.07 similar to 2 ng/g Gd. The method is applicable to analyses for 7 similar to 8 N pure metal and compounds.