Microanalysis of solid samples by laser ablation and total reflection X-ray fluorescence

Total reflection X-ray fluorescence (TXRF) was applied in the analysis of metallic and ceramic materials after LA. Sample material was evaporated by the focussed radiation of a pulsed Nd:YAG laser and collected directly on a quartz or Plexiglas disc commonly used as a sample carrier for TXRF. Iron-Cr and Cu-Zn binaries, a high-alloy steel sample, and a high-temperature superconducting ceramic (YBa2Cu3O6.9) were chosen for analysis. Only microgram quantities of sample material mere removed per laser shot, and only a few nanograms of sample were deposited on the sample carrier. This minute amount was sufficient for TXRF analysis. The mass of individual elements detected by TXRF mas at the pg-level, so that a mass fraction in the order of 1 mg g(-1) could be determined. Quantification was achieved by addition of an internal standard. Accurate results were obtained after a single laser shot of the deposits of the binary samples, the steel sample and the ceramic material. Deviations from the correct composition mere only observed for the Cu-Zn binaries when using multiple laser shots. The combination of LA with TXRF detection enables ultra-microanalysis of solids without laborious sample preparation steps. By repetitive laser pulses upon neighbouring spots a microdistribution analysis may become possible with a lateral resolution of about 10 mu m.