MICROANALYSIS OF SOLID SAMPLES BY LASER-ABLATION AND TOTAL-REFLECTIONX-RAY-FLUORESCENCE

Total reflection X-ray fluorescence (TXRF) was applied in the analysis of metallic and ceramic materials after LA. Sample material was evapo rated by the focussed radiation of a pulsed Nd:YAG laser and collected directly on a quartz or Plexiglas disc commonly used as a sample carr ier for TXRF. Iron-Cr and Cu-Zn binaries, a high-alloy steel sample, a nd a high-temperature superconducting ceramic (YBa2Cu3O6.9) were chose n for analysis. Only microgram quantities of sample material mere remo ved per laser shot, and only a few nanograms of sample were deposited on the sample carrier. This minute amount was sufficient for TXRF anal ysis. The mass of individual elements detected by TXRF mas at the pg-l evel, so that a mass fraction in the order of 1 mg g(-1) could be dete rmined. Quantification was achieved by addition of an internal standar d. Accurate results were obtained after a single laser shot of the dep osits of the binary samples, the steel sample and the ceramic material . Deviations from the correct composition mere only observed for the C u-Zn binaries when using multiple laser shots. The combination of LA w ith TXRF detection enables ultra-microanalysis of solids without labor ious sample preparation steps. By repetitive laser pulses upon neighbo uring spots a microdistribution analysis may become possible with a la teral resolution of about 10 mu m.