Electron-Capture Mass Spectrometry: A Powerful Tool in Biomedical Trace Level Analysis

This review focuses on the advances in electron capture mass spectrometry. Electron-capture (EC) is a sensitive ionisation technique for mass spectrometry providing selectivity towards electrophoric compounds. Recent advances in instrumentation have led to a more widespread application of this method in biomedical and pharmaceutical analysis. After a brief introduction to EC-mass spectrometry (MS), potential targets for EC-MS analysis are defined and enhancement of sensitivity by electrophoric derivatisation is discussed. A wide range of applications is selected, including prostanoid analysis in biomedical systems (with the oxidative stress indicators isoprostanes) and the trace level analysis of endogenous low-molecular weight compounds. Application to the trace level gas chromatography-negative ion chemical ionization MS (GC-NICI-MS) analysis of complex glucuronides is also demonstrated, as well as a wide range of drugs analysed in human blood. The review should point out the versatility and unique sensitivity of the technique, making it useful for basic research in medicinal chemistry, as well as clinical diagnosis, pharmaceutical and toxicological applications.