The analysis of drugs of abuse in clinical and post-mortem samples

The Specialised Clinical Chemistry laboratory at Sheffield Teaching Hospitals analyses urine samples from Substance Misuse clinics to monitor patients who are undergoing a drug addiction treatment programme. In addition, the department also screens for drugs of abuse (DoA) in post-mortem blood and urine samples. A DoA screen is currently performed on all samples/cases using a range of immunoassays which are prone to false positives. This means that positive screening results from Substance Misuse clinic patients have to be confirmed using gas-chromatography mass-spectrometry (GCMS). Positive post-mortem screening results are quantitated using a range of individual assays performed using high-performance liquid-chromatography (HPLC) and GCMS. This confirmation and quantitation is time consuming, delaying the reporting of results, and requiring a large amount of manual input.

The aim of this project is to develop an assay using liquid chromatography high resolution-mass spectrometry (LC-HRMS) that can be used for the simultaneous screening and confirmation of drugs of abuse in urine samples and can be adapted for the simultaneous screening and quantitation of drugs of abuse in post-mortem samples. The performance of the LC-HRMS assay will be assessed by comparing the range of compounds detected in patient samples using the LC-HRMS with compounds detected using GCMS screening approaches. The concentrations measured using the LC-HRMS screen will also be compared to those obtained using GCMS and HPLC analysis. Samples provided by international quality assurance schemes will be analysed to determine the accuracy of the LC-HRMS method.

Outputs

Rab E, Flanagan RJ, Hudson S. Detection of fentanyl and fentanyl analogues in biological samples using liquid chromatography-high resolution mass spectrometry. Forensic Sci Int. 2019;300:13-18.

Presentations

• FOCUS 2018 Association of Clinical Biochemistry award finalist London Toxicology Group
• March 2018: Responding to the Changing Patterns of Substance Misuse: Fentanyl and its Analogues