Market Profile: Electron Transfer Dissociation (ETD)
May 1st 2007Electron transfer dissociation, generally referred to as ETD, is a new fragmentation technique that is associated with ion trap LC–MS instrumentation. Despite being widely introduced less than two years ago, demand for the technique is increasing rapidly.
Basic Fundamental Parameters in X-Ray Fluorescence
May 1st 2007The "fundamental parameters" approach to calibration in X-ray fluorescence is unique because it is based upon the theoretical relationship between measured X-ray intensities and the concentrations of elements in the sample. This theoretical relationship is based upon X-ray physics and the measured values of fundamental atomic parameters in the X-ray region of the electromagnetic spectrum. In this tutorial, an introduction to the means of calibration is provided based upon a simplified instrument–sample geometry, thus eliminating some of the mathematical details of the traditional derivations.