Determination of Trace Elements in Bauxite Using Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry on Lithium Borate Glass Beads

Abstract

Quantification of trace element contents in bauxite by solution ICP-MS and other analytical methods that rely on conventional dissolution techniques can be challenging, because the refractory nature of common host minerals complicates complete digestion. Fusion with lithium borate, frequently used as a sample preparation method for XRF analysis of solid materials, avoids these problems. This manuscript documents that subsequent analysis of the low-dilution glass beads by laser ablation ICP-MS is a fast, accurate and precise method for determining trace element mass fractions in samples of bauxite and similar natural materials. The method was validated by determining thirty trace elements, including thirteen rare earth elements, in international reference materials for bauxite (ANRT BX-N, NIST SRM 69b, NIST SRM 696, NIST SRM 698) and iron formations (CCRMP FeR-2). Trace elements were typically measured to within 20% of reference values with an 'external' precision of < 20% RSD. Measurement results from various deposits in Suriname illustrate the procedure's effectiveness for studies concerning chemical properties and origin of bauxite.