A number of analytical approaches and methods for determination of biologically active thiol compounds have been developed , including both stationary (for example voltammetry, chronopotentiometry, polarography) and flow techniques (like liquid chromatography (LC) , gas chromatography (GC) and capillary electrophoresis (CE)) . With LC systems, there are numerous detection methods, including UV detection, mass spectrometry, and electrochemical detection. Each method has its advantages and limitations and may serve a particular need in analysis.

A Protocol for the Determination of Free Thiols (spectrophotometry)

http://v.web.umkc.edu/vanhornj/freethiol.htm

Few articles based on HPLC and spectrophotometry are added for persual.

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Can ICP give accurate concentration of S in the solution? 

Among the methods available for measurement of S, inductively coupled plasma atomic emission spectrometry (ICP‐AES) has been proved to be accurate and rapid.

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