Quantitative analysis of sulfhydryl compounds in biological Samples: Advancements in chromatographic and mass spectrometric techniques

Thiol (HS), commonly referred to as sulfhydryl, constitutes a vital functional group characterized by a sulfur atom bonded to hydrogen. It plays a pivotal role in various chemical compounds, including mercaptans (R-SH), thiophenol (Ar-SH), and thiol carboxylic acids (commonly known as sulfur carboxylic acids), contributing to their distinct properties. Sulfhydryl-containing compounds, such as mercaptans, homocysteine, cysteine, and glutathione, have been closely linked to numerous physiological and metabolic disorders. Consequently, the precise measurement and analysis of sulfhydryl compounds in biological samples hold significant implications in unraveling the physiological underpinnings of certain diseases and identifying potential biomarkers. A plethora of methodologies for quantifying sulfhydryl compounds have emerged, harnessing diverse analytical techniques. Electrochemical approaches exploit the redox activity of sulfhydryl compounds, but face challenges associated with elevated detection potentials and the susceptibility of oxidation products to adsorb onto electrode surfaces. In tandem, numerous nanosensors and fluorescent probes have been developed for sulfhydryl compound determination in biological samples. However, these methods exhibit limitations, including extended reaction times and susceptibility to fluctuations in fluorescence intensity arising from medium conditions and probe concentrations. In contrast, chromatography and mass spectrometry have emerged as robust, precise, and reproducible techniques for sulfhydryl compound analysis. This review explores a range of analytical methodologies employed for assessing sulfhydryl compounds in biological samples, with a particular emphasis on the versatility and effectiveness of chromatography and mass spectrometry, both when used individually and in combination, spanning the years from 2011 to 2023.