Chromatography - Bartelt

LLG CHROMATOGRAPHY CATALOGUEChromatographyChromatography columns/GC Reagents, GC SeptaSilylation reagentsUsually the term silylation in GC stands for replacement of active hydrogen atoms by aMACHEREY-NAGELtrimethylsilyl group (TMS derivative). Sometimes, however, trialkylsilyl groups or dimethylalkylsilylgroups with longer alkyl chains are used for derivatisation. The trialkylsilyl group increases volatility andenhances thermal stability of the sample. Silylation can be catalysed either acidic by addition of TMCS orbasic by addition of pyridine (e. g. for sterically hindered functionalities like tert. alcohols)Silylation reagents - BSTFA, SILYL-991N,O-bis-trimethylsilyl-trifluoroacetamideMACHEREY-NAGELm.w. 257.4, Bp 40°C (12mm Hg), density d20°/4° = 0.961BSTFA:R = CF3powerful trimethylsilyl donor with approximately the same donor strength as the non-fluorinated analogue BSAadvantage of BSTFA over BSA: greater volatility of its reaction products (particularly useful for GC of some lower boilingTMS amino acids.BSTFA is nonpolar (less polar than MSTFA), and can be mixed with acetonitrile for improved solubility. For silylatingfatty acid amides, hindered hydroxyls and other compounds, which are difficult to silylate (like secondary alcohols andamines), we recommend BSTFA + 1% trimethylchlorosilane (TMCS), available under the designation SILYL-991.Description Capacity PK Cat. No.mlBSTFABSTFABSTFASILYL-991 (BSTFA - TMCS (99:1)SILYL-991 (BSTFA - TMCS (99:1)SILYL-991 (BSTFA - TMCS (99:1)11010150100201520114.001 4866.803 3204.001 4874.001 5114.001 5104.001 509Due to their purpose, derivatisation reagents are very reactive substances. For this reason they should be stored cool and protected from moisture.The derivatisation reagents are supplied in vials with crimp caps for easy access with a syringe. Vials with pierced sealing disks have limited stability and shouldbe used immediately.Silylation with BSTFA or SILYL-991 (BSTFA + 1 % TMCS)Procedure:Add 0.5 ml silylation reagent to 1 – 10 mg sample; if necessary, add some solvent (normally pyridine or DMF[dimethylformamide] are used). Heat to 60 – 80 °C for 20 min to increase the reaction rate.BSTFA MN Appl. No. 213092 · SILYL-991 MN Appl. No. 213093E & OE.101