NBOMe instability in whole blood

The stability of NBOMes, potent new psychoactive substances, in whole blood was studied over 180 days.

We present a fully validated liquid chromatography–tandem mass spectrometry method to quantify seven NBOMes (25B-, 25C-, 25D-, 25E-, 25G-, 25H- and 25I-NBOMe) in whole blood, and a 180 day stability at two analyte concentrations and three storage temperatures [room temperature (RT), 4 °C and −20 °C].

Calibration curves were linear over 0.1–10 ng/mL, with intra- and interday imprecision (% relative standard deviation) and bias (%) not greater than 8.1 %. For low concentration (0.3 ng/mL) samples at RT, 25B-, 25C-, 25I- and 25E-NBOMe decreased by more than 20% after 15 days and were undetectable after 30 days. All NBOMes were below the limit of quantification (LOQ; 0.1 ng/mL) when stored at RT for 60 days. At 4 °C, 25B-, 25C-, 25I-, 25G-, 25D- and 25E-NBOMe (0.3 ng/mL) decreased by more than 20% (up to 54%) after 180 days. Except for 25H-NBOMe, all high concentration (8 ng/mL) NBOMes decreased by more than 20% after 15 days at RT, and high concentrations of 25B-, 25C-, and 25I-NBOMe were unstable at 4 °C after 180 days. All analytes were stable for 180 days at −20 °C. Extracts of low, medium and high quality control samples were stable when reinjected after 32 h storage on the autosampler at 15 °C. All analytes were stable after three freeze-thaw cycles at −20 °C.

Based on the potential for NBOMe instability prior to testing, it is recommended to refrigerate whole blood for NBOMe analysis up to 90 days, and to freeze samples for longer term storage.