title: Comparison of inductively coupled plasma spectrometry techniques for the direct determination of rare earth elements in digests from geological samples.
abstract: Inductively coupled plasma quadrupole mass spectrometry (ICP-QMS), ICP sector field mass spectrometry (ICP-SFMS) and ICP atomic emission spectrometry (ICP-AES) were compared with regard to the direct determination of rare earth elements (REEs) in geological samples. In order to reduce the polyatomic interferences occurring in ICP-QMS, the use of a cooled spray chamber was optimized, obtaining a significant decrease of the oxide ions formation (about 50%) and a consequent mitigation of the interfering effects. Precision and accuracy of the method were demonstrated by the analyses of sediment and soil certified reference materials. ICP-SFMS working in high-resolution mode also provided accurate results, with similar precision to ICP-QMS (RSD%: 3-8%) and comparable or better limits of detection. Quantification limits of the procedures were 18-52 ng g(-1) and 10-780 ng g(-1) for sector field- and quadrupole-ICP-MS, respectively. Accurate and precise determination of most REEs was also achieved by ICP-AES using both pneumatic and ultrasonic nebulization, after a careful selection of the emission lines and compensation for non-spectral interferences by internal standardization. The three techniques were finally applied to glaciomarine sediment samples collected in Antarctica, providing comparable analytical data on REE abundance and depth pattern.
authors.affiliation: Department of Chemistry and Industrial Chemistry, University of Genoa, Via Dodecaneso 31, 16146 Genoa, Italy.
authors.forename: Francisco
authors.initials: F
authors.lastname: Ardini
authors.forename: Francesco
authors.initials: F
authors.lastname: Soggia
authors.forename: Francesco
authors.initials: F
authors.lastname: Rugi
authors.forename: Roberto
authors.initials: R
authors.lastname: Udisti
authors.forename: Marco
authors.initials: M
authors.lastname: Grotti