Thiols belong to crucial biologically important molecules. They are considered to be multitasking molecules due to variety of functions. Nevertheless regulating of heavy metal ions levels and scavenging of reactive oxygen species are ones of the most important actions of thiols in an organism. Both low molecular molecules as cysteine and glutathione and protein metallothionein possess the mentioned function. The aim of this work was to utilize electrochemical techniques coupled with liquid chromatography for determination of thiols.