Analysis of Pressed Pellets
The pressed powder pellet sample preparation technique allow trace elemt determinations, with limits of detection below 1 ppm for selected elements. In addition, comparison of XRF determinations, esp. Rb, Sr, Y, Zr, and Nb, with ICP-MS analysis is a very powerful and necessary quality control mechanism for analytical results. Over the several decades in which XRF has been used in geochemical analysis, there has been a slow but steady evolution of the instrumentation resulting in improved sensitivities and lowered detection limits. Using a combination of improved crystals and longer counting times, the limit of detection for Rb, Y and Nb have been reduced to 0.6 -0.7 ppm.