XRF, or X-ray fluorescence, is the process of firing highly energetic X-ray radiation at various substances in order to determine what the elemental composition of those substances is. By observing how much radiation is absorbed by the material, scientists can figure out which chemical elements are constitutive of the materials under analysis. In order to ensure the reliability of this procedure, samples must be prepared using particular preparation techniques. Furthermore, since XRF equipment, such as XRF spectrometers, are so expensive, failing to prepare your samples properly constitutes an enormous waste of money. Preparation techniques depend on the form of the substance in question.
Instructions
Preparation
1. Obtain a sample to be analyzed. This may be a solid, powder or liquid substance. These are typically delivered to the XRF analyst by the person or organization who has requested the results. Common organizations requesting XRF analysis include cement industry professionals, environmental organizations and metal and plastic production companies.
2. Grind the substance into small grains. If the sample in question is solid substance, such as a slag, ore or plastic, it must be ground into very small grains of the same size, in order to produce a reliable analysis. There are many types of grinders available. Be sure to use a grinder that is appropriate for the substance in question. Liquid samples need not be subjected to this step and can be analyzed in their current form.
3. Create beads of substances that are difficult to analyze due to problems associated with their grain size. Some substances are best analyzed in bead form. Take the powdered substance and press them into beads using the bead mold. Fuse the sample into larger beads by heating them in a crucible to between 900 and 1300 degrees.
4. When you have a homogeneously-sized sample, the XRF preparation process is complete. The substance may be bombarded with X-rays using the XRF spectrometer as per the XRF analysis process.
Tags: small grains, substance question
