A novel methodology using liquid-liquid extraction with low temperature partitioning (LLE-LTP) and paper spray mass spectrometry (PS-MS) was developed to identify and quantify benzodiazepines in beverages. Four types of alcoholic beverages usually consumed in parties and bars were spiked with 5 distinct benzodiazepines (diazepam, alprazolam, bromazepam, clonazepam, and cloxazolam) simulating a drug-facilitated crime occurrence. The direct PS-MS analysis of the spiked beverages revealed a remarkable matrix effect with an unclear detection of protonated benzodiazepines. However, by the application of the LLE-LTP using liquid nitrogen, a prompt and doubtless detection of such compounds was achieved. The quantification potential of the LLE-LTP/PS-MS methodology was demonstrated by using beer as matrix, diazepam as target analyte and cloxazolam as an internal standard. Figures of merit (linearity, limit of detection, linear dynamic range, relative standard deviation, and recovery) were determined and adequate values were obtained. In conclusion, we demonstrated herein that the LLE-LTP/PS-MS methodology has potential to be applied directly at the crime scene through of a portable mass spectrometer and a thermal container for the transport of liquid nitrogen.

Paper spray mass spectrometry (PS-MS) is applied as a simple, fast, and reliable methodology to detect cocaine in samples seized on streets.

The PS-MS technique proved to be suitable for an in situ and 'near' real-time analysis of the dynamic equilibrium involving the redox of MB in aqueous medium. The data clearly demonstrated how the redox equilibrium shifts depending on the disturbance caused to the system.

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