Quantitative trace analysis with X-ray fluorescence in the scanning electron microscope
The potential of a scanning electron microscope will be enhanced markedly by adapting the X-ray fluorescence for material analysis. The illuminating system “rontgenbox” enables the analyst to execute analyses in the concentration range from 100 percent down to the low ppm range without time consuming preparation steps. X-ray intensities of traces are measured for different anodes in the elemental range fromZ=11 to 90 (sodium to thorium).
A study was carried out on the separation of active anthraquinone ingredient in Chinese rhubarb using High-Speed Countercurrent Chromatography with acid-base accommodationt. Trifluoroacetic acid (TFA) was used as the retaining acid and ammonia liquor as the eluent base. The solvent system was n-hexane-acetic ester-methanol-water (ratio by volume was 9 ∶1 ∶5 ∶5). The separative product was confirmed as five pure anthraquinone of Chinese rhubarb by High Performance Liquid Chromatography (HPLC).