Comparative stability assessment of synthetic cannabinoids in dry blood spots and blood using UHPLC-MS/MS:...

Synthetic cannabinoids are the most numerous group of new psychoactive substances (NPSs) in Europe. The diversity and quantity of newly emerging synthetic cannabinoids make it difficult to monitor intoxications with these compounds, especially in view of their stability after biological material collection.

In this study, 17 NPSs were analyzed to determine their stability in whole blood and dry blood spots (DBSs). The samples were stored at room temperature (DBS), 4 °C (DBS and whole blood), and -20 °C (whole blood). Analyses were performed using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry. The stability study lasted 365 days, monitoring the degradation rate of analytes. Moreover, the effect of chemical structure on analyte stability was assessed.

Results proved that the stability of analytes depended on both storage conditions and their chemical structure. Four compounds showed better long-term stability in DBS samples, whereas seven of the tested compounds exhibited significantly better long-term stability in whole blood samples.

Studies indicate a strong correlation between the stability of synthetic cannabinoids and both their chemical structure and storage conditions. DBS cards can provide equal or enhanced stability compared to whole blood, which makes it advisable to collect biological material in both forms to help maximize analytical options in forensic and toxicological investigations.