| 摘要 |
<p>Chromatographic stationary phase comprising a silica support modified with higher hydrocarbon groups attached via silicon-oxygen links and one or more end-capping groups attached via silicon-oxygen links, in which the end-capping groups are derived from mono- and/or di-methylhydrogensilanes. A chromatographic stationary phase (A) comprising a silica support with one or more coupling agents of formula R 1>R 2>R 3>SiO- (I) attached via Si-O links and one or more silane end-capping groups of formula R 4>(CH 3)(H)SiO- (II) and/or uOSi(H)(CH 3)O- (III) attached via Si-O links, in which R 1>, R 2>, R 3>H or 1-30C hydrocarbyl, with the proviso that at least one of these groups is a 4C or higher hydrocarbyl group; R 4>H or methyl . Independent claims are included for (1) a chromatographic stationary phase (B) for use in reverse-phase chromatography, comprising a silica support with one or more hydrophobic ligands and a methylsilane and/or dimethylsilane end-capping group, all attached by Si-O links (2) a method (M1) for the production of (B) by reacting a silica support containing surface silanol groups with silane coupling agent(s) of formula R 1>R 2>R 3>SiX (IV) and then reacting the unreacted silanol groups with end-capping reagents of formula R 4>(CH 3)(H)Si-Y (V), CH 3(H)SiY 2 (VI) and/or CH 3(H)(R 8>)Si-Z-Si(R 9>)(H)CH 3 (VII) (3) a method (M2) for making a chromatographic stationary phase with end-capping groups by reacting a functionalised silica with attached silane coupling agent(s) containing hydrophobic ligands and with unreacted surface silanol groups, with one or more end-capping reagents which can form monomethyl- and dimethyl-silyl groups attached to the silica by the unreacted silanols . X, Y : halogen, OR 5> or NR 6>R 7>; R 5>1-30C alkyl; R 6>, R 7>H or 1-30C alkyl; R 8>, R 9>H or methyl; Z : N or a covalent bond.</p> |
