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Gas Chromatography (GC) Derivatization Alkylation As with other derivatization reagents, alkylation reagents reduce molecular polarity by replacing active hydrogens with an alkyl group. These reagents are used to modify compounds having acidic hydrogens, such as carboxylic acids and phenols. Alkylation reagents can be used alone to form esters, ethers, and amides—or they can be used in conjunction with acylation or silylation reagents. A two-step approach is commonly used in the derivatization of amino acids, where multiple functional groups on these compounds may necessitate protection during derivatization. Due to the availability of reagents and their ease of use, esterification (the reaction of an acid with an alcohol in the presence of a catalyst to form an ester) is the most popular method of alkylation. Alkylation reagents are available in several configurations that enable the formation of a variety of esters. Alkyl esters are stable, and can be formed quickly and quantitatively. By altering the length of the substituted alkyl group, retention of the derivative can be varied. In addition to the formation of simple esters, alkylation reagents can be used in extractive procedures where biological matrices may be present. GC Chiral Derivatization GC analysis of enantiomeric compounds on nonracemic or achiral stationary phases requires the use of enantiopure derivatization reagents. These reagents generally target one specific functional group to produce diastereomers of each of the enantiomeric analytes. From the resulting chromatograms, calculations are conducted to determine the enantiomeric concentration of the analyte. 44 For more information visit www.registech.com/gc
Guide to GC Derivatization Methods/Functional Groups GC Derivatization Method Functional Group Silylation Acylation Alkylation Active Hydrogens BSTFA, BSTFA/TMCS, PFPOH/PFPA DMF Dialkylacetals, Deriva-Sil, Hydrox-Sil, TBH MSTFA, MTBSTFA, TMSI Carboxylic Acids BSTFA, Hydrox-Sil Conc., PFPOH/PFPA BF 3 /Methanol, MTBSTFA, TMSI BF 3 /n-Butanol, DMF Dialkylacetals, TBH Alcohols and Phenols: BSA, BSTFA/TMCS, HFBI, Fluorinated anhydrides DMF Dialkylacetals, unhindered and HMDS, MTBSTFA/t-BDMCS (HFBA, PFPA, TFAA), PFB-Br/TBA-H-SO 4 , moderately hindered MBTFA, MCF* TBH Alcohols and Phenols: BSTFA/TMCS, Deriva-Sil, Fluorinated anhydrides DMF Dialkylacetals, highly hindered Deriva-Sil Conc. (HFBA, PFPA, TFAA), PFB-Br/TBA-H-SO 4 , HFBI, PFBCl TBH Amines: BSTFA, MTBSTFA/t-BDMCS Fluorinated anhydrides DMF Dialkylacetals, primary and secondary (HFBA, PFPA, TFAA), HFBI, TBH MBTFA, PFBCl, TPC* Amides BSA, BSTFA, BSTFA/TMCS, HFBI DMF Dialkylacetals, Deriva-Sil Conc. Amino Acids BSTFA, TMSI HFBI (+ Silylation) DMF Dialkylacetals, TBH 3N HCl in n-Butanol Catecholamines TMSI Fluorinated anhydrides (HFBA, PFPA, TFAA), HFBI Carbohydrates and Sugars HMDS, Hydrox-Sil AQ, TMSI MBTFA Inorganic Anions BSTFA, MTBSTFA Nitrosamines HFBA Sulfonamides BSTFA Fluorinated anhydrides DMF Dialkylacetals, (HFBA, PFPA, TFAA) PFB-Br/TBA-H-SO 4 Derivatization reagents are listed in alphabetical order, not in order of preference. *For Chiral Analysis Source: Knapp, D.R. Handbook of Analytical Derivatization Reactions; John Wiley and Sons: New York, 1979. For more information visit www.registech.com/gc 45
Page 1: Chromatography Catalog
Page 4 and 5: Table of Contents IAM Drug Discover
Page 6 and 7: Regis Technologies, Inc. Quality Pr
Page 8 and 9: Chiral Stationary Phases Chiral Chr
Page 10 and 11: Chiral Stationary Phases Pirkle Chi
Page 16 and 17: Chiral Stationary Phases Protein-Ba
Page 18 and 19: Chiral Stationary Phases Crown Ethe
Page 20 and 21: RAM Direct Injection (Restricted Ac
Page 22 and 23: ISRP (Internal Surface Reversed Pha
Page 24 and 25: SPS (Semi-Permeable Surface) SPS Co
Page 26 and 27: RAM Direct Injection Applications C
Page 28 and 29: IAM Chromatography Immobilized Arti
Page 30 and 31: Drug Discovery-Predicting Drug Memb
Page 32 and 33: IAM.PC.DD2 % Absorption of Inverted
Page 34 and 35: IAM Fast Screen Mini Column + H 3 C
Page 36 and 37: IAM Fast Screen Mini Column Regis T
Page 38 and 39: Ultrapure Ion Pairing Reagents and
Page 40 and 41: Ultrapure Ion Pairing Reagents and
Page 42 and 43: Regis Quaternary Amines ( Q-Series)
Page 44 and 45: Derivatization Derivatization is pr
Page 48 and 49: Silyation Reagents BSA N,O-Bis(trim
Page 50 and 51: Silyation Formulations Deriva-Sil
Page 52 and 53: GC Chiral and Specialty Derivatizat
Page 54 and 55: GC Chiral and Specialty Derivatizat
Page 56 and 57: Supercritical Fluid Chromatography
Page 58 and 59: RegisSEP GMP SFC Separation Service
Page 60 and 61: Custom Synthesis The Chemistry of P
Page 62 and 63: 60 For more information visit www.r
Page 64 and 65: Index Listed Alphabetically P Page
Page 66: Order Information Shipping (continu

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