Quadrupole Time-of-Flight Mass Spectrometry: A Paradigm Shift in Toxicology Screening Applications

Abstract

The screening of biological samples for the presence of illicit or legal substances is an important frontline tool in both clinical and forensic toxicology. In the clinical setting, drug screening is a useful tool for the clinician in improving patient care and guiding treatment. Analytical approaches for the screening of drugs in biological samples are extensive and well documented, though many rapid screening techniques often lack appropriate sensitivity and specificity, requiring careful clinical interpretation. The continuous emergence of new psychoactive substances presents a considerable analytical challenge in maintaining up-to-date methods for the detection of relevant drugs. Adapting and validating methods for the detection of new substances can be a complicated and costly undertaking. There is also a considerable lag time between the emergence of new drugs and the release of commercial assays for detection. Quadrupole time-of-flight mass spectrometry (Q-TOF-MS) has gained considerable attention over the last decade as an analytical technique that is capable of meeting the challenges of a rapidly changing drug landscape. Exhibiting both high sensitivity and specificity in drug detection, Q-TOF-MS also allows methods to be rapidly updated for newly emerging psychoactive agents. The coupling of Q-TOF-MS with techniques such as liquid or gas chromatography can provide both rapid and comprehensive screening solutions that are gaining popularity in the clinical laboratory setting.

Figure 1

Full width at half maximum (FWHM) method for the calculation of instrument resolution.

Figure 2

Schematic diagram of a quadrupole time-of-flight mass spectrometer.