Determination of lanthanum and rare earth elements in bovine whole blood reference material by ICP-MS after coprecipitation preconcentration with heme-iron as coprecipitant

An analytical method for the determination of lanthanide elements in the bo vine whole blood reference material (IAEA A-13) has been investigated by in ductively coupled plasma mass spectrometry (ICP-MS). The bovine whole blood reference material was digested with HNO3 and HClO4, and then the pH of th e digested solution was adjusted to 12 with 3 M sodium hydroxide aqueous so lution. In this experimental procedure, lanthanide elements in the blood sa mple were coprecipitated with iron mainly derived from heme-iron in blood i tself. In order to minimize matrix effects due to iron, excess iron in the analysis solution was removed by solvent extraction using methyl isobutyl k etone (MIBK) prior to the determination of lanthanide elements by ICP-MS. T he recoveries of all lanthanide elements were almost quantitative in the re covery test. In consequence, it has been found that all lanthanide elements in bovine whole blood reference material are at the wide concentration ran ge of 0.90 pg/g for Tm similar to 1880 pg/g for Ce.