Determination of 37 fentanyl analogues and novel synthetic opioids in hair by UHPLC-MS/MS and its application to authentic cases

The recent emergence of new fentanyl analogues and synthetic opioids on the drug market poses a global public health threat. However, these compounds cannot typically be identified using existing analytical methods. In this study, we aimed to develop and validate a rapid and sensitive method based on ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) for the simultaneous determination of 37 fentanyl analogues and novel synthetic opioids in hair samples. Hair samples (20 mg) were extracted by cryogenic grinding in an extraction medium of methanol, acetonitrile, and 2 mmol/L ammonium acetate (pH 5.3). Following centrifugation of the samples, the analytes were separated using a WATERS Acquity UPLC HSS T(3) column. The limits of detection (LODs) and limits of quantification (LOQs) ranged from 0.5 to 2.5 pg/mg and from 2 to 5 pg/mg, respectively. The intraday and interday precisions were within 13.32% at LOQ, low, medium, and high levels. The accuracies were within the range of 85.63–116.1%. The extraction recoveries were in the range of 89.42–119.68%, and the matrix effects were within the range of 44.81–119.77%. Furthermore, the method was successfully applied to the detection and quantification of fentanyl and sufentanil in hair samples from two authentic cases. Thus, this method has great potential for detecting fentanyl analogues and novel synthetic opioids in forensic work.