In our complex world, scientists and other technicians use a variety of sophisticated testing to help protect us and keep us safe. These highly technical testing systems and laboratory protocols can be used to identify the composition of products and materials that we use or are found in our environment. This advanced type of testing is applied across a variety of disciplines, ranging from engineering and chemistry to geology, materials science and pharmaceuticals. One of these key testing methodologies is XRD, which was discovered and introduced in 1912 at the University of Munich’s Institute of Theoretical Physics. For this breakthrough Max von Laue, who originated the experiment, received the Nobel Prize in 2014.
When you perform XRD, or X-Ray Powder diffraction, the initial step is to take part of the substance and grind it into fine powder. From there, XRD can be used to analyze the unique crystalline structure of the sample. During this testing, the X-rays are diffracted by the unique types of atoms in the material being studied. The diffraction patterns that appear provide information about the arrangement of the atoms within the crystalline structure. By measuring the unique angles and intensities of the X-rays that are scattered during testing, we can then determine the specific crystalline structure and composition.
XRD and the Pharmaceutical Industry
A tremendous amount of effort goes into keeping the medicines and pharmaceuticals we take safe. As part of this effort, XRD analysis is used to help develop and test new drugs that are designed to restore people to good health. With XRD, scientists can assure drug quality by accurately identifying the exact components and minerals that each drug contains. This methodology is also used to help assure quality control throughout all stages of the manufacturing process.
XRD testing allows manufacturing companies to improve their product formulation, and can contribute to increasing the stability of the pharmaceuticals across a variety of environments. Testing can also be done to determine the bioavailability of the products, and to analyze the compatibility of excipients.
Environmental Testing of Acid Mine Drainage
Drainage from mines occurs when groundwater or surface water drains from an abandoned or active mine. At some of these mines, pyrite (iron sulfide mineral) can become exposed. When it reacts with water and air, it can form a mixture of dissolved iron and sulfuric acid. Further acid runoff can add to the environmental damage by dissolving heavy metals like lead, mercury and copper into the local water systems. This harmful runoff can contaminate local drinking water sources, and disrupt reproduction cycles and growth of animals and aquatic plants.
With XRD testing, environmental scientists can quantify and identify the proportions of each different mineral within a drainage sample that is being tested. Soil from areas damaged by acid mine drainage can be fully analyzed, and scientists can then determine which small-grained precipitates and secondary minerals are present. In addition to identifying the mineral properties, XRD can also be used to shed light on the solubility and transport of these elements.
XRD Analysis and Remote Sensing
In certain areas of the country, damaging landslides and mudflows can occur. To help identify the potential for these future disasters, scientists utilized XRD along with remote sensing to examine clay-rich rock formations found on some of the Cascade volcanoes. These rocks were being studied because they had been hydrothermally altered, and it was believed they could directly contribute to potential slides and damaging flows of mud.
With XRD, scientists could specifically identify the exact minerals present in these rocks. This testing methodology gave scientists data on the borates and saline materials that were present. Based on the detailed test results derived by studying these samples, scientists were able to understand and identify key absorption features.
