Determination of rare-earth elements in rock samples by an improved high-performance ion chromatography

Abstract

An analytical technique of rare-earth elements (REE) in rock samples using a high-performance ion chromatography (HPIC) is described. The REE in rock samples were separated from other elements using a conventional ion-exchange column, and then measured by the HPIC. α-hydroxyisobutyric acid and Arsenazo III were used for eluants and a post-column reagent for the HPIC, respectively. The use of a high-resolution HPIC column enabled to analyze all fourteen REE without any interference from Y and other transition metals. The REE concentrations determined for twelve Geological Survey of Japan rock reference samples, having varied major element compositions, showed good agreement with the recommended values and the values recently obtained by inductively coupled plasma-mass spectrometry (ICP-MS). This HPIC technique provides an inexpensive means to obtain high-quality data of all fourteen REE in rock samples as small as <50 mg, and potential for wide geochemical applications as an alternative to ICP-MS. cisely and rapidly. However, the REE analysis using all these methods requires significantly large instrumental, running and maintenance costs. In addition, ICP-AES requires relatively large sample size (500 to 1000 mg) for precise REE determination and has difficulties in analyzing low levels of Pr, Tb and Tm (Walsh et al., 1981). INAA needs access to a nuclear reactor facilities for REE analysis, and is also generally unsuitable for the determination of Pr, Gd, Dy, Ho and Er (Barnes and Gorton, 1984). ID-TIMS is the most precise and accurate method for REE analysis, but not applicable to the determination of monoisotopic REE (Pr, Tb, Ho and Tm). Therefore the development of an alternative method that is capable of analyzing all REE in small amount of rock samples at a reasonable cost still has great signifi-

Evaluation of superficially and fully porous particles for HILIC separation of lanthanide–polyaminocarboxylic species and simultaneous coupling to ESIMS and ICPMS

“…The associated analytical methods are currently under development. It must be noted that because of the numerous Ln industrial applications, the separation of the series of lanthanide ions has been reported with other separation techniques such as ionic chromatography, 41 ion pairing reversed-phase chromatography, 42 capillary electrophoresis 43 and isotachophoresis. 44 All these techniques require the addition of ion pairing and/or complexing agents in the mobile phases for Ln elution and the use of complexing agents as constituents of background electrolyte to insure differential Ln migration.…”

Quantitative Measurement of Rare Earth Elements in Brines: Isolation from the Charged Matrix Versus Direct LA‐ICP‐MS Measurements – A Comparative Study

“…Another method of sample ionisation, except for ICP that is commonly used for the REEs analyses, is thermal ionisation, in particular, isotope dilution-thermal ionisation mass spectrometry (ID-TIMS). Details about the advantages and disadvantages of these techniques can be found elsewhere (e.g., Ishikawa et al 2003). Briefly, ICP-MS is the method of choice for quantification of REEs if: (a) a precise quantification of all the REEs including the mono-isotopic elements (Pr, Tb, Ho and Tm) is required, (b) the expected mass fractions of REEs in samples are at the level of 1 µg g -1 and below, (c) samples are unique and limited quantities of material are available for analyses, and (d) nuclear reactor facilities are not accessible (nowadays INAA has been practically replaced by ICP-MS due to its complexity and associated costs).…”

High‐Performance Liquid and Ion Chromatography: Separation and Quantification Analytical Techniques for Rare Earth Elements

“…Traditionally, during HPLC separations using HIBA (as the mobile phase), it has been found that Y co-elutes with Dy (e.g., Cassidy 1988;Verma 1991a, b, Na et al 1995, Santoyo and Verma 2003, Raut et al 2004, or less commonly with Ho (Watkins et al 1995, Inoue et al 1996. Probably in one study only (Ishikawa et al 2003; see Table 1), Y was completely separated from all lanthanides (Lu-La) with a 5 μm column maintained at 40 °C, the conventional mobile phase HIBA (but with a high concentration of 1.0 mol l -1 ), and a UV-Vis detection system. A different way to overcome this problem has been the use of an ICP-MS or ICP-AES detection system.…”

“…Among the use of HPLC and HPIC for determination of the REEs, geological applications have represented an important research area (e.g., Cassidy 1988, Stray and Dahlgren 1995, Watkins et al 1995, Verma et al 2002, Ishikawa et al 2003, Santoyo et al 2006. Geological samples are generally characterised by complex mineralogical matrices.…”