Cope-LLG Catalogue 2018

1468 14. Chromatography Gas chromatography/GC reagents GENERAL CATALOGUE EDITION 20 E & OE. Silylation reagents - BSTFA, SILYL-991 N,O-bis-trimethylsilyl-trifluoroacetamide m.w. 257.4, Bp 40 °C (12mm Hg), density d20°/4° = 0.961 BSTFA: R = CF 3 powerful trimethylsilyl donor with approximately the same donor strength as the non-fluorinated analogue BSA advantage of BSTFA over BSA: greater volatility of its reaction products (particularly useful for GC of some lower boiling TMS amino acids. BSTFA is nonpolar (less polar than MSTFA), and can be mixed with acetonitrile for improved solubility. For silylating fatty acid amides, hindered hydroxyls and other compounds, which are difficult to silylate (like secondary alcohols and amines), we recommend BSTFA + 1 % trimethylchlorosilane (TMCS), available under the designation SILYL-991. MACHEREY-NAGEL Description Capacity PK Cat. No. ml BSTFA BSTFA BSTFA SILYL-991 (BSTFA - TMCS (99:1) SILYL-991 (BSTFA - TMCS (99:1) 1 10 10 1 50 20 1 5 20 1 4.001 486 6.803 320 4.001 487 4.001 511 4.001 510 Due 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 should be used immediately. Acylation reagents for GC - Bisacylamides Acylation with fluorinated acid amides is recommended for alcohols, primary and secondary amines as well as for thiols under mild, neutral conditions. MBTFA also forms very volatile derivatives with carbohydrates. by-products: corresponding neutral acylamides, which can be easily removed due to their high volatility; because of neutral conditions and favourable chromatographic properties often removal of the bisacylamide is not necessary. Thus sample preparation is much more convenient. MBTFA /MBHFBA N-methyl-bis(trifluoroacetamide) MBTFA m.w. 223.08, Bp 123 - 124 °C (760mm Hg), density d20°/4° = 1.55, CF 3 - CO - N(CH 3 ) - CO - CF 3 MACHEREY-NAGEL Description Capacity PK Cat. No. ml MBTFA MBTFA MBTFA 1 10 10 20 1 5 7.401 143 7.510 796 6.228 605 Due 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 should be used soon. Acylation reagents for GC - Anhydrides Acylation with fluorinated acid anhydrides can be used for alcohols, phenols, carboxylic acids, amines, amino acids and steroids forming volatile, stable derivatives suited for FID as well as for ECD detection. by-products of acylation with anhydrides: corresponding acids excess reagent and the acid formed have to be removed Heptafluorobutyric acid anhydride (HFBA) m.w. 410.06, Bp 106 - 107 °C (760mm Hg), C 3 F 7 - CO - O - CO - C 3 F 7 density d20°/4° = 1.665 MACHEREY-NAGEL Description Capacity PK Cat. No. ml HFBA HFBA HFBA 1 10 10 20 1 5 4.001 480 4.001 479 4.001 481 Alkylation reagents for GC - Trimethylsulphonium hydroxide TMSH (0.2M in methanol) M.G. 94.06 MACHEREY-NAGEL Description Capacity PK Cat. No. ml TMSH TMSH TMSH 1 1 10 10 20 5 7.086 147 7.083 308 4.001 512