Liquid phase microextraction based on natural deep eutectic solvents of psychoactive substances from biological fluids and natural waters

In this paper, natural deep eutectic solvents (NADES)-based for liquid phase microextraction (LPME) is proposed for the isolation of different psychoactive substances in water and biological fluids followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The NADES composition was optimized (L-menthol:octanoic acid, 1:2 M ratio) prior to the study of the extraction conditions such as sample and elution volumes, obtaining up to 16-fold preconcentration factor. Next, the quality parameters were studied including linearity from LOQs (0.0006-0.05 μg L-1) to 100 μg L-1, precision values (expressed as relative standard deviation, RSD≤8 %) and recoveries above 70 % in most cases. Certified saliva and serum samples were analyzed by the proposed method to assess the accuracy of the developed procedure, providing values statistically comparable to the certified ones. In addition, the proposed methodology was evaluated by applying green metrics (AGREEprep tool) and the obtained values were compared with those reported for a similar procedure using LPME with common organic solvents such as chloroform or dichloromethane, outperforming them in both cases, which points out the potential of this method from the sustainability point of view.

Micro-paper-based analytical device decorated with metal-organic frameworks for the assay of synthetic cannabinoids in oral fluids coupled to ion mobility spectrometry

A new concept of paper-based device has been developed combining the advantages of cellulose supports and the rich surface chemistry of metal-organic frameworks (MOFs). The composite, named as NH2-UiO-66@paper, has been developed for the isolation of synthetic cannabinoid receptor agonists (SCRAs) in oral fluids, trying to mimic the interactions of those compounds with the human CB1R and CB2R receptors, mainly governed by hydrogen bonding and π-interactions with serine and histidine residues. MOF selection (UiO-66) and functionalization of the ligand (2-aminoterephthalic acid) has been done according to the following criteria: (i) water stability of the selected MOF, and (ii) promoting appropriate interactions with SCRAs due to the MOF nature. NH2-UiO-66@paper composite has been characterized in depth and the results confirmed that the material is stable at the temperature selected for thermal desorption (230 °C). Furthermore, the developed method provided appropriate precision values (RSD < 12%) and a limit of detection as low as 10 ng using ion mobility spectrometry as analytical technique. Lastly, the method has been successfully applied to the isolation of several synthetic cannabinoids from oral fluids. This method claims to be an interesting approach for expanding the combination of MOFs with sustainable support and represents a promising alternative to sophisticated and non-portable systems due to the negligible sample treatment required and the simplicity of the operation, which can be applied with screening purposes.

Determination of synthetic cannabinoids in oral fluids by liquid chromatography with fluorescence detection after solid-phase extraction

Synthetic cannabinoids are one of the most consumed new psychoactive substances, being absolutely necessary the development of analytical methodologies for the determination of these substances in biological fluids. In this study, a liquid chromatography with fluorescence detection (LC-FD) method has been developed for the analysis of 8 synthetic cannabinoids in oral fluids. The method has been validated in terms of linearity, precision and extraction recoveries, giving limits of detection as low as 0.7 µg L^-1, and limits of quantification of 2.6 µg L^-1. Different silica and polymeric commercial solid sorbents such as C18, Supel-Select HLB, EB2 Extrabond^Ⓡ and SampliQ-OPT were tested, concluding that Supel-Select HLB provided quantitative recoveries for the extraction of synthetic cannabinoids in oral fluids.•Analysis of synthetic cannabinoids in oral fluids.•Analytical procedure based on liquid chromatography with fluorescence detection.•Sample treatment based on solid phase extraction with HLB cartridges.