Advances in energy-dispersive X-ray fluorescence (original) (raw)

Recently, two new instruments for X-ray tluorescence analysis (XRF) with interesting features for geochemical applications came to the market. Both instruments were designed to improve the peak to background ratio, the principal factor limiting the sensitivity of XRF. Total reflection XRF (TXRF) was designed to analyse extremely small sample amounts. An instrument, using polarised X-rays (P-XRF) for excitation, is designed to reduce scattered background in spectra of bulk samples. The performance of both instruments was compared with conventional XRF-methods and ICP/MS. Results for GXR-I, GXR-2, GXR-3, GXR-4 and GXR-6 obtained with TXRF and P-XRF are in good agreement with literature data. The effective amount of sample, analysed by TXRF was 200 pg only and detection limits of _ I p.g/g were achieved. P-XRF shows considerable improved detection limits (0.25-0.5 kg/g) for bulk samples for elements with atomic numbers 42-5 I (Mo-Sb) compared with conventional XRF-methods. Keywords: microanalysis: energy-dispersiev X-ray lluorercence (EDXFR): total-reflection X-ray fluorescence (TXRF): polarised X-rays; multi-element analysis 0375.6742/97/$17.00 Copyright 0 1997 Elsevier Science B.V. All rights reserved PII SO375-6742(96)00053-Z