Incorporation of an Environmentally Friendly Method for the Detection of Fentanyl and its Analogs in Oral Fluid.

Oral fluid is considered a favorable matrix for the identification of drug intake mainly because of its simple, observed, non-invasive collection. Fentanyl and fentanyl analog use, misuse, overdose, and deaths are currently occurring at an alarming rate in the USA. The law enforcement community, the Food and Drug Administration (FDA) and the Centers for Disease Control (CDC) are all keenly aware of the urgency in addressing an unmet public health need to identify opioid overdose in individuals as rapidly as possible. As part of a National Institute of Justice grant, the present study was intended to develop and validate an environmentally friendly, rapid, sensitive quantitative method using liquid chromatography coupled to tandem mass spectral detection (LC-MS/MS) for fentanyl and fentanyl analogs in oral fluid collected using the nform rapid test device. Oral fluid samples were subjected to liquid-liquid extraction incorporating bio-renewable solvents where possible, reducing the environmental footprint of the assay. A buffer/salt free mobile phase was employed consisting of 0.1% formic acid in water (95%): 0.1% formic acid in methanol (5%) at a flow rate of 0.8 mL/min; the run time was 4.5 minutes, again reducing environmental impact in terms of salt and solvent usage. The method included fentanyl, 4-anilino-N-phenethylpiperidine; (4-ANPP; desproprionyl fentanyl), acetyl fentanyl, carfentanil, p-fluorofentanyl, valeryl fentanyl, p-fluorobutyrylfentanyl, furanyl fentanyl and benzoyl fentanyl as well as xylazine, which is often detected with fentanyl. The method was validated according to ANSI/ASB 036 (2019) Standard Practices for Method Validation in Forensic Toxicology.