Quantification and distribution of trace elements in fusion bead and pressed pellet specimens using a table top micro-X-ray fluorescence spectrometer

Abstract

Pressed pelletization and fusion bead methods are two very important sample preparation techniques for X-Ray Fluorescence (XRF) analysis. Hence, along with the assessment of these two techniques with respect to its analytical capabilities, it is also very important to study the elemental homogeneity in the prepared specimens. The distribution of trace elements in the specimen prepared using pressed pelletization and fusion bead method were studied using a recently installed table top Micro-XRF (μ-XRF) spectrometer. The spectrometer is equipped with focussing polycapillary lens to obtain the X-ray spot size of 51.3 μm × 33.5 μm. An area of 4 mm × 4 mm was scanned using μ-XRF and the data obtained were used for the elemental mapping of the trace elements in those sample specimens. It was observed that the distribution of trace elements in the specimens depend on their concentration. The elements were distributed more homogeneously in bead than in pellet specimens and the homogeneity increases with the elemental concentration in both the specimens. The μ-XRF determined elemental concentrations of the trace elements in fused bead and pressed pellet specimens were in good agreement with the expected values. However for lower elemental concentration, it was observed that fused bead specimen technique is better. The fused bead technique was utilised to determine trace elemental concentration in a real soil sample.