Liquid–liquid extraction-assisted SERS-based detection of clonazepam in spiked drinks

Abstract

In this study we aimed to combine the liquid–liquid extraction with low-temperature partition (LLE-LTP) sample preparation method with the SERS analytical technique to detect clonazepam in beverages that are commonly consumed at parties, in bars, and in nightclubs to simulate the analysis of beverages involved in drug-facilitated crimes. Chemometric tools were used to build a classification model to identify the presence of clonazepam in the analyzed drinks. One-class strategy was employed to build classification model. The performance of the SIMCA model was also assessed using sensibility and efficiency for the test set, which was determined to be 0.92 and 0.96, respectively The classification model allowed the appropriate and satisfactorily classification of drinks, even for those drinks that presented a matrix effect during analysis, which were subjected to a quick extraction procedure prior to analyzing them. The methodology proposed here could be used at crime scenes, where portable equipment could be utilized, and presents great potential for application in forensic laboratories, where fast and simple analytical methods must be employed routinely.