Kara Lynch (Presenter)
University of California San Francisco
Bio: Dr. Kara Lynch is an Associate Professor of Laboratory Medicine at the University of California San Francisco and the Co-Director of the Core Laboratory (Clinical Chemistry and Toxicology) at Zuckerberg San Francisco General Hospital and Trauma Center. She received her PhD in Biochemistry from the University of Wisconsin and did a post-doctoral fellowship in Clinical Chemistry in the COMACC approved training program at UCSF. Her primary area of research is in Clinical Toxicology. Her laboratory conducts studies aimed at identifying and quantifying toxins, drugs of abuse and adulterants in biological specimens using mass spectrometry and correlating the findings with clinical pathologies.
Authorship: Kara L. Lynch and Fatemeh Fouladkou
Department of Laboratory Medicine, University of California San Francisco
| Short Abstract The emergence of illicitly manufactured synthetic opioids including fentanyl and analogues represents a significant escalation of the ongoing opioid overdose epidemic in the United States. Synthetic opioids have been identified as adulterants in heroin and counterfeit opioid pills and are often consumed unknowingly. The purpose of this project was to validate the detection of 13 fentanyl analogues/synthetic opioids using a high resolution mass spectrometry drug screen and develop a comprehensive suspect analysis approach for the detection of synthetic opioid metabolites and emerging synthetic opioids. |
Long Abstract
Introduction
The emergence of illicitly manufactured synthetic opioids including fentanyl and analogues represents a significant escalation of the ongoing opioid overdose epidemic in the United States. Synthetic opioids have been identified as adulterants in heroin and counterfeit opioid pills and are often consumed unknowingly. The true extent of the synthetic opioid epidemic is underappreciated due to the lack of routine diagnostic monitoring. The use of high resolution mass spectrometry offers many advantages for the identification of synthetic opioids. Data is acquired in an untargeted manner and can be retrospectively analyzed for new and emerging synthetics. Tentative identification of unknowns can be made without the availability of a reference standard. The purpose of this project was to validate the detection of 13 fentanyl analogues/synthetic opioids using a high resolution mass spectrometry drug screen and develop a comprehensive suspect analysis approach for the detection of synthetic opioid metabolites and emerging synthetic opioids.
Methods
Urine samples were diluted 1:5 and chromatographic separation was performed using a Kinetex C18-column with a 10-minute gradient from 2%-100% organic. Data was collected on a SCIEX TripleTOF®5600 operating in positive-ion mode using a TOF-MS survey scan with IDA-triggered collection of high resolution product ion spectra (20 dependent scans). Data review was done using PeakView and MasterView software. Limits of detection and matrix effects were determined for 13 synthetic opioids. LOD was defined as the lowest concentration (100, 50, 25, 10, 5 ng/mL) for which the drug met scoring criteria for positive identification (combined score >70%, with 70% weight given to library match and 10% weight given to each of mass error, retention time error and isotope pattern difference) in duplicate injections and had a signal-to-noise ratio >20:1. Matrix effects were determined by calculating the mean signal intensity in urine (N=3 matrix samples, tested in triplicate at 3 concentrations) minus the mean signal intensity in water (N=3 water samples, tested in triplicate at 3 concentrations) divided by the mean signal intensity in water and multiplied by 100%. Each analytical standard was injected using a dedicated product ion scan method in order to obtain a library spectra that was added to our in-house library for data analysis.
Results
The analytically defined LOD and matrix effects (average for all concentrations) were as follows (LOD ng/mL, % matrix effects): fentanyl (5 ng/mL, -9%), norfentanyl (2.5 ng/mL, -15%), butyryl fentanyl (5 ng/mL, -14%), 3-methyl fentanyl (2.5 ng/mL, -11%), tetrahydrofuran fentanyl (2.5 ng/mL, -10%), acryl fentanyl (2.5 ng/mL, -16%), acetyl fentanyl (1 ng/mL, -26%), carfentanil (2.5 ng/mL, -11%), beta-hydroxythiofentanyl (2.5 ng/mL, -20%), furanyl fentanyl (2.5 ng/mL, -17%), para-fluorofentanyl (2.5 ng/mL, -19%), para-fluorobutyryl fentanyl (2.5 ng/mL, -8%), sufentanil (5 ng/mL, -11%), alfentanil (1 ng/mL, -15%), and, U-47700 (10 ng/mL, -33%). A library spectrum was added to our in-house library for each analyte. In addition, a larger suspect data analysis method was developed. An extraction ion chromatogram data analysis list was created that contains the extraction mass (M+H) for additional synthetic opioids, metabolites defined in published reports, and potential emerging synthetic opioids. This list can be used for tentative identification of unknowns prior to the purchase of an analytical standard. The method described here has been used to identify the synthetic opioids U-47700 and carfentanil in cases referred to our clinical laboratory from the northern California poison control center. The presentation will discuss the use of this method in these cases.
Conclusions & Discussion
We have developed a high resolution mass spectrometry method for the detection of synthetic opioids. This method had been validated for 13 synthetic opioids and is designed to tentatively detected additional emerging synthetic opioids using a suspect analysis method with a curated list of potential synthetic opioids and metabolites.
References & Acknowledgements:
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