What is the most common process used for confirmatory testing in toxicology?

Gas chromatography-mass spectrometry (GC/MS) is widely recognized as the most common process for confirmatory testing in toxicology due to its high sensitivity and specificity in identifying and quantifying substances in biological samples. The technique combines the separation capabilities of gas chromatography with the identification power of mass spectrometry, allowing for precise analysis of complex mixtures.

In toxicology, confirmatory testing is essential because it follows initial screening tests and is used to validate the presence of a particular substance. GC/MS is particularly effective for this purpose because it can separate volatile compounds and produce a unique mass spectrum that can be matched to known standards, ensuring accurate identification.

While other methods like liquid chromatography-tandem mass spectrometry (LC-MS) are also used, particularly for non-volatile and hydrophilic substances, GC/MS remains the gold standard for many toxicological applications, especially when analyzing drugs and their metabolites. Thin-layer chromatography and infrared spectroscopy, while useful in certain contexts, do not provide the same level of sensitivity and specificity needed for confirmatory testing in toxicology.