Journal of Chromatography & Separation Techniques
Open Access

Liquid-chromatography high-resolution mass spectrometry for untargeted toxicology analysis

International Summit on Current Trends in Mass Spectrometry

July 13-15, 2015 New Orleans, USA

Alan H B Wu

Posters-Accepted Abstracts: J Chromatogr Sep Tech

Abstract :

Testing for drugs abuse in blood and urine for clinical and forensic toxicology occurs in two steps: immunoassay screening followed by mass spectrometry (MS). While immunoassays are rapid and inexpensive, some assays suffer from poor sensitivity and specificity. Gas chromatography coupled with mass spectrometry is used for confirmatory analysis, but results are usually not available for real-time patient management. The implementation of liquid chromatography (LC)-tandem MS has reduced the pre-analytical steps needed for confirmatory analysis. However, matches to pre-existing MS libraries are required for general unknown screening. LC-high-resolution (HR) MS, such as with time-of-flight and Orbitrap MS technologies and use of soft ionization enable detection of unknown compounds based on precise molecular formula. These technologies are more powerful for general unknown screens because library spectra may not be available for many compounds, especially novel designer drugs, and because the toxicology laboratory does not have standards and controls for the hundreds of thousands of low molecular weight compounds that can cause poisonings. Although results are not definitive without standards, and cannot be used alone for forensic purposes, presumptive results can be reported for clinical toxicology cases. Confirmation analysis performed retrospectively with acquisition of the appropriate standards. In this manner, results can be reported quickly enabling medical decisions that can have an impact on patient outcomes. This lecture will describe LC-HR-MS techniques with examples of clinical cases solved.