Analysis of Selenium-Containing Compounds

Considering the close chemical similarity of thiols and selenols it is not surprising that selenols, diselenides and selenenyl sulfides are electrochemically active. Killa and Rabenstein used dual Au/Hg amperometric detection to measure these compounds following RPLC in the presence of OSA. The optimum potential was found to be -1-0.15 V vs Ag/AgCl. With correct choice of chromatographic conditions, selenols could also be resolved from the thiols occurring in biological matrices. 

For pharmacokinetic and metabolic studies it is essential that thiols and disulfides are not measured in isolation. Pre-column reduction procedures partially overcome this problem, but qualitative data on the disulfides are lacking. Postcolumn reduction can be restrictive since sensitivity depends on the ability of the reactor to reduce disulfides in some cases this is impossible. HPLC-ED is proving in some cases to be the method of choice for this dual application. 

Where sample numbers are large and assays can be performed within a few days of sample collection HPLC-ED using metal electrodes offers both speed and sensitivity. Good column maintenance is essential to avoid poor chromatography, broad late-eluting peaks and also ghost peaks. 

Patai (ed). The Chemistry of the Sulfur-containing Functional Groups, Wiley, Chichester, 1993. 

Ashworth, The determination of sulfur-containing groups, 3rd edn. Academic Press, London, 1977. 

---

Variable temperature NMR has been utilized in the conformational analysis of selenium-containing compounds such as the ring inversion process of phenylselenenylcyclohexane, 2,11 -diselena[3.3]... 

---