N-Methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) was first synthesized by Manfred Donike in 1969(1). The primary task of MSTFA is to insert a trimethylsilyl protecting group by exchanging active hydrogen atoms in polar molecules possessing -OH, -COOH, -NH2, -NRH or -SH groups. Shown here as an example of the reaction of MSTFA with an alcohol(2).
By inserting the protecting group, the reaction products become less polar decreasing interaction and consequently increasing volatility. In subsequent GC/MS analysis for structural identification, the TMS derivatives can then be evaporated at lower temperatures and unwanted decomposition reactions can be prevented (improved fragmentation in the mass spectrometer)(2/3).
Today, trimethylsilylation remains a very important step in sample preparation for doping analysis. In addition to catecholamines and stimulants such as amphetamine or ephedrine, performance-enhancing steroid hormones (anabolic steroids) can also be converted into stable derivatives, thus decisively improving their detection sensitivity. The following is the trimethyliodosilane catalyzed TMS derivatization of testosterone(4).
Addendum:
The 1972 Olympic Games in Munich are regarded as the beginning of systematic doping controls in sport. With the development of suitable detection methods for degradation products of synthetic hormones, testing for anabolic steroids has also been carried out since the 1976 Summer Games in Montreal. The use of the endogenous hormone testosterone has also been banned since 1984.
Further information about derivatization reagents from MACHEREY-NAGEL: Derivatization reagents for GC (EN)
References:
(1) M. Donike, J. Chromatogr. A. Band 42, 1969, p.103-104
(2) D. Urbach, Toxichem Krimtech 2012;79(3):137
(3) http://www.dshs-koeln.de/institut-fuer-biochemie/analyse-methoden/derivatisierung/
(4) http://www.dshs-koeln.de/institut-fuer-biochemie/analyse-methoden/anabolika/
