Silylation Reagents
Silylation is the most widely used derivatization procedure for sample analysis by GC. The popularity of silylation reagents is enhanced by their ease of use and formation of derivatives. In silylation, an active hydrogen is replaced by an alkylsilyl group such as trimethylsilyl (TMS) or t-butyldimethylsilyl (t-BDMS).
Compared to their parent compounds, silyl derivatives are more volatile, less polar, and more thermally stable. As a result, GC separation is improved and detection is enhanced.
Silylation reagents are generally moisture sensitive, requiring them to be sealed to prevent deactivation. The derivatives of TMS reagents are also more sensitive. In response to this difficulty, t-BDMS reagents were intrduced, which enabled the formation of derivatives 10,000 times more stable to hydrolysis than the TMS ethers.
Both TMS and t-BDMS reagents are suitable for a wide variety of compounds, offer excellent thermal stability and can be used under a variety of GC conditions and applications.
BSA
N, O-Bis(trimethylsilyl)acetamide
CAS 10416-59-8
- Forms highly stable TMS derivatives, with most organic functional groups, under mild reaction conditions.
BSTFA-Regisil®
BSTFA + TMCS (1%, 10%)
N, O-Bis(trimethylsilyl)trifluoroacetamide
CAS 21149-38-2
- BSTFA reacts faster and more completely than BSA, due to trifluoroacetamide leaving group
- The high volatility of BSTFA and its byproducts results in non-co-elution of early eluting peaks
- Highly volatile and stable products result in low detector noise and fouling
- Excellent solubility and solvency
- Addition of TMCS catalyzes reactions of hindered functional groups and other difficult functionalities such as secondary hydroxyls and amines.
HMDS
Hexamethyldisiazane
Weak TMS donor, used in silylating mixtures
MSTFA
N-Methyl-N-(trimethylsilyl)trifluoroacetamide
CAS 24589-78-4
- Most volatile of the TMS-acetamides
- Useful in the analysis of volatile trace materials where derivatives elute near reagent or byproduct peak
MTBSTFA
MTBSTFA +1% t-BDMCS
N-Methyl-N-(t-butyldimethylsilyl)trifluoroacetamide
CAS 77377-52-7
- Replaces reactive hydrogens to form t-BDMS derivatives
- Derivatization is usually complete upon dissolution with this exceptionally strong, yet mild silylating reagent
- MTBSTFA derivatives are 104 times more stable to hydrolysis than their corresponding TMS derivatives
- Produces easily interpreted mass spectra for GC/MS
- Addition of t-BDMCS catalyzes reactions of hindered alcohols and amines
TMCS
Trimethylchlorosilane
Catalyst used to increase reactivity of other silylation reagents
TMSI
Trimethylsilylimidazole
- Potent, selective TMS donor that reacts with hydroxyls but not amines or amides
- Derivatives wet sugar samples, hindered hydroxyl groups in steroids, and amino acids in fluorinated acylation reagents
| Product | Size | Regis
Product # | U.S. Price |
| TMSI |
| TMSI | 10 x 1 gram | 270401 | $55.00 |  |
| TMSI | 5 gram | 270402 | $28.00 | |
| TMSI | 25 gram | 270403 | $67.00 | |
| TMCS |
| TMCS | 25 gram | 270601 | $30.00 | |
| TMCS | 100 gram | 270602 | $60.00 | |
| MTBSTFA |
| MTBSTFA | 5 x 1 gram | 270241 | $81.00 | |
| MTBSTFA | 2 x 5 gram | 270242 | $88.00 | |
| MTBSTFA | 25 gram | 270243 | $165.00 | |
| MTBSTFA + 1% t-BDMCS | 5 x 1 gram | 270141 | $81.00 | |
| MTBSTFA + 1% t-BDMCS | 2 x 5 gram | 270142 | $88.00 | |
| MTBSTFA + 1% t-BDMCS | 25 gram | 270143 | $165.00 | |
| MTBSTFA + 1% t-BDMCS | 10 x 1 gram | 270144 | $135.00 | |
| MSTFA |
| MSTFA | 10 gram | 270589 | $65.00 | |
| MSTFA | 10 x 1 gram | 270590 | $75.00 | |
| MSTFA | 25 gram | 270593 | $82.00 | |
| MSTFA | 100 gram | 270594 | $300.00 | |
| HMDS |
| HMDS | 25 gram | 270651 | $30.00 | |
| HMDS | 100 gram | 270652 | $60.00 | |
| BSTFA-Regisil |
| Regisil® RC-1 (BSTFA) | 10 x 1 gram | 270111 | $70.00 | |
| Regisil® RC-1 (BSTFA) | 4 x 5 gram | 270112 | $63.00 | |
| Regisil® RC-1 (BSTFA) | 25 gram | 270113 | $70.00 | |
| Regisil® RC-1 (BSTFA) | 100 gram | 270114 | $190.00 | |
| BSTFA+10% TMCS-Regisil |
| Regisil® RC-3 (BSTFA+10% TMCS) | 10 x 1 gram | 270131 | $70.00 | |
| Regisil® RC-3 (BSTFA+10% TMCS) | 4 x 5 gram | 270132 | $63.00 | |
| Regisil® RC-3 (BSTFA+10% TMCS) | 25 gram | 270133 | $70.00 | |
| Regisil® RC-3 (BSTFA+10% TMCS) | 100 gram | 270134 | $190.00 | |
| Regisil® RC-3 (BSTFA+10% TMCS) | 1000 gram | 270135 | $830.00 | |
| BSTFA +1% TMCS-Regisil |
| Regisil® RC-2 (BSTFA +1% TMCS) | 1000 gram | 270126 | $830.00 | |
| Regisil® RC-2 (BSTFA+1% TMCS) | 10 x 1 gram | 270121 | $70.00 | |
| Regisil® RC-2 (BSTFA+1% TMCS) | 4 x 5 gram | 270122 | $63.00 | |
| Regisil® RC-2 (BSTFA+1% TMCS) | 25 gram | 270123 | $70.00 | |
| Regisil® RC-2 (BSTFA+1% TMCS) | 100 gram | 270124 | $190.00 | |
| BSA |
| BSA | 10 x 1 gram | 270501 | $55.00 | |
| BSA | 4 x 5 gram | 270502 | $52.00 | |
| BSA | 25 gram | 270503 | $65.00 | |
| BSA | 100 gram | 270504 | $145.00 | |