Comparison of MTBSTFA and BSTFA in derivatization reactions of polar compounds prior to GC/MS analysis.
In this study, MTBSTFA and BSTFA, which are among the preferred derivatization reagents for silylation were both tested on derivatization of six different groups of polar chemicals to get information about usefulness in terms of sensitivity and specificity of both reagents. Tested compound groups were nitrophenols and methoxyphenols, sterols and sugars, dicarboxylic acids and hydroxylated polycyclic aromatic hydrocarbons. It was found that MTBSTFA-derivates produce characteristic fragmentation patterns presenting mainly the fragments [M](+), [M-57](+) and [M-131](+), of which [M-57](+) is generally dominant on the mass spectrogram. BSTFA-derivates mainly show the fragments [M](+), [M-15](+) and [M-89](+) whereof the molecular ion [M](+) is generally dominant. It was also found that steric hindrance and molecular mass play a very important role in the choice of the best suited derivatization reagent: compounds with sterically hindered sites derivatized with MTBSTFA produce very small analytical responses or no signal at all, and compounds with high molecular mass produce no characteristic fragmentation pattern when derivatization is performed with BSTFA. It was also found that MTBSTFA-derivatization facilitates separation of isomer analytes, suggesting its choice in combination to semi-polar columns, whilst BSTFA seems better for sterically hindered compounds. Findings were confirmed with applications of both reagents to biological and environmental matrices (urine and atmospheric aerosols).
Schummer
Claude
C
Centre de Géochimie de la Surface, UMR 7517, CNRS-Universitè Louis Pasteur, Laboratoire de Physico-Chimie de l'Atmosphère, Strasbourg Cedex, France. claude.schummer@lns.etat.lu
Delhomme
Olivier
O
Appenzeller
Brice M R
BM
Wennig
Robert
R
Millet
Maurice
M
D000081:Acetamides; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation / Q000379:methods; D003998:Dicarboxylic Acids / Q000032:analysis; D005463:Fluoroacetates; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D008956:Models, Chemical; D009596:Nitrophenols / Q000032:analysis; D017646:Organosilicon Compounds / Q000032:analysis*; D010636:Phenols / Q000032:analysis; D012680:Sensitivity and Specificity; D013696:Temperature; D014269:Trifluoroacetic Acid / Q000032:analysis; D014297:Trimethylsilyl Compounds / Q000032:analysis*; D016482:Urinalysis / Q000295:instrumentation / Q000379:methods*
D000081:Acetamides; D003998:Dicarboxylic Acids; D005463:Fluoroacetates; D009596:Nitrophenols; D017646:Organosilicon Compounds; D010636:Phenols; D014297:Trimethylsilyl Compounds; C047270:N,N-bis(trimethylsilyl)-2,2,2-trifluoroacetamide; C059151:N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide; D014269:Trifluoroacetic Acid