Rapid Comm Mass Spectrometry - 2022 - Kim - Development of a rapid in‐situ analysis method using sheath‐flow probe.pdf (2.98 MB)
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Development of a rapid in-situ analysis method using sheath-flow probe electrospray ionisation-mass spectrometry (sfPESI-MS) for the direct identification of cocaine metabolites in dried blood spots

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posted on 18.11.2022, 11:52 authored by Ayoung Kim, Paul KellyPaul Kelly, Matthew TurnerMatthew Turner, Jim ReynoldsJim Reynolds

RATIONALE: Small amounts of biofluid samples are frequently found at crime scenes, however existing gold standard methods such as LC-MS frequently require destructive extraction of the sample before a time-consuming analysis which puts strain on forensic analysis providers and can preclude further sample analysis. This study presents the application of Sheath Flow Probe Electrospray Ionization - Mass Spectrometry (sfPESI-MS) to the direct analysis of drug metabolites in dried blood spots as a high throughput, minimally destructive alternative.

METHODS: A rapid direct analysis method using a sfPESI ionisation source coupled to an Orbitrap Exactive mass spectrometer was applied to detect cocaine metabolites (benzoylecgonine, BZE, cocaethylene, CE, and ecgonine methyl ester, EME) from dried blood spots. An optimisation study exploring the use of different chemical modifiers (formic acid and sodium acetate) in the sfPESI probe extraction solvent was conducted to enhance the sensitivity and reproducibility of the sfPESI-MS method.

RESULTS: Optimization of the extraction solvent significantly enhanced the sensitivity and reproducibility of the sfPESI-MS method. A quantitative response over a 5-point calibration range 0.5 to 10 μg/mL was obtained for benzoylecgonine (R2 = 0.9979) and cocaethylene (R2 = 0.9948). Limits-of-detection (LoD) of 1.31, 0.29 and 0.15 μg/mL were achieved for EME, BZE and CE respectively from 48-hour aged dried blood spots with % RSD across the calibration range ranging between 19 - 28 % for [BZE+H]+, 13 - 21 % for [CE+H]+ and 12 - 29 % for [EME+H]+.

CONCLUSIONS: A rapid (< 20 seconds) quantitative method for the direct analysis of cocaine metabolites from dried blood spots which requires no prior sample preparation was developed. While the LoD achieved for BZE (LoD: 0.29 μg/mL) was above the UK threshold limit of exposure for drug driving (0.05 μg/mL), the method may be suitable for use in identifying overdose in forensic analysis.

History

School

  • Science

Department

  • Chemistry

Published in

Rapid Communications in Mass Spectrometry

Volume

37

Issue

2

Publisher

John Wiley & Sons Ltd.

Version

VoR (Version of Record)

Rights holder

© The Authors

Publisher statement

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Acceptance date

18/10/2022

Publication date

2022-10-24

Copyright date

2022

ISSN

0951-4198

eISSN

1097-0231

Language

en

Depositor

Dr Jim Reynolds. Deposit date: 25 October 2022

Article number

e9422

Ethics review number

R18-P034