August 2023

Drug evidence seized during the police raid | Image Credit: © wellphoto - stock.adobe.com

Shifted-excitation Raman difference spectroscopy (SERDS) is a technique that is capable of reducing the interference caused by fluorescence and improve the potential of Raman for distinguishing drug compounds in seized samples with fluorescent additives. Here, 43 drugs were analyzed to show the practical application of SERDS.

Test tube row. Concept of medical or science laboratory, liquid drop droplet with dropper in blue red tone background, close up, macro photography picture, AI Generated | Image Credit: © Vladislava - stock.adobe.com

Using internal standards is a common technique to correct for variations in sample matrices and the effect this has on analyte intensities. There are several basic criteria to be considered when using internal standards: selection of appropriate internal standards, the concentration added to the solutions analyzed, setting up in the correct view (axial vs. radial), how to introduce the internal standard to the solutions to be analyzed, and evaluating the resulting data. Each of these topics are considered and suggestions presented.