Quantitative evaluation of the composition of synthetic cannabinoid receptor agonists (SCRA) in infused papers and herbal materials seized in Brazilian prisons

Abstract

This study describes the identification and quantification of synthetic cannabinoid receptor agonists (SCRA) in infused paper and herbal material samples, seized in prisons located in São Paulo state, Brazil. The selected samples (23 infused paper and 3 herbal material samples) were previously analyzed by the São Paulo State Police, in a qualitative analysis by gas chromatography–mass spectrometry (GC–MS) using full-scan and library search for identification. Afterward, these samples were analyzed by liquid chromatography-tandem mass spectrometry in a triple quadrupole (LC-MS/MS) system operating in MRM mode for determination of the majority and the possible minority SCRA present in the samples. For the LC-MS/MS analysis the samples were extracted with methanol and diluted in a proportion of 1:1000 and 1:10,000. All substances identified by GC-MS were also identified by LC-MS/MS, but not the opposite, showing GC-MS full-scan method employed were unable to detect those SCRA presented in lower concentration levels. The presence of a single SCRA in the samples was observed in 11 samples (27.5%), while in 29 samples (72.5%) two or more SCRA were identified. The SCRA most frequently detected in the samples were MDMB-4en-PINACA and ADB-BUTINACA, present in 72% and 70% of the samples, respectively. The concentration of SCRA shown great variability, ranging from 0.2 μg/infused paper to 3000 μg/infused paper. In cases with more than one SCRA detected, the minority compounds did not exceed the concentration of 50 μg/infused paper. Comparing two different samples of a single seizure it was possible to identify the same substances but in different concentration levels, or different compositions (mixtures). The highest concentration of SCRA present in the infused papers was for the cases involving MDMB-4en-PINACA as the major compound, reaching until 3000 μg/infused paper, but this SCRA was also found as minority in other cases, with concentrations as low as 0.9 μg/infused paper. Among all samples, 4F-MDMB-BUTICA was detected in only one case, at a concentration of 125 μg/infused paper. For the three samples of plant material, ADB-BUTINACA appears as the major compound, with the presence of other minor SCRA ranging from 0.2 to 5 μg/mg. These results shows that the studied samples did not present homogeneity in the composition and concentration levels, even when comparing a single case, but it seems that some SCRA are commonly found together. The presence of different SCRA in the same sample may contribute to the increase in the toxicity of these compounds, which reinforces the need to obtain quantitative and qualitative data from the seized samples.