1. Context

In recent years, Raman spectroscopy has become an indispensable method for rapid analysis in forensic science. There are a number of reasons why this technique is such a powerful and effective analytical tool: it is a non-contact, non-destructive technique, requiring minimal sample quantity (sub-micrometer spatial resolution) and little or no sample preparation. The information obtained by Raman spectroscopy includes chemical identification and molecular structure. These features are very useful for the study of illicit substances, as the technique enables the detection of minute differences that may arise from the composition, origin of the sample or method of synthesis. Unlike infrared spectroscopy, Raman spectroscopy is compatible with aqueous solutions, making it possible to analyze both wet and liquid samples. Analysis through glass vials or plastic bags is possible thanks to the coupling...