Gas-liquid chromatography of nucleosides

摘要: The aims of this investigation were to study the completeness silylation nucleosides with three different reagents, bis(trimethylsilyl)trifluoroacetamide (BSTFA), bis(trimethylsilyl)acetamide (BSA) and trimethylsilylimidazole (TMSI), investigate effect solvents (acetonitrile, pyridine, dimethylformamide, chloroform, methylene chloride, hexane, benzene, toluene) on quantitation derivatization. Closed-tube silylations performed BSTFA, BSA, TMSI, for most complete silylation, optimal time, temperature, molar excess reagent were: 150°-15 min 225 excess; 60°-3 1000 120°-2 h 250 excess. Also, seven major minor carried out using a TMSI at 25° 5 sonication, conditions as described above reagents. silylating strengths determined by increase in RWR (= weight response nucleoside/weight pyrene) values, are summarized amino group containing silylated room temperature BSTFA > under BSA TMSI. efficiency hydroxyl group-containing was = BSA. Significantly lower values obtained all when made 25°-5 min, excess, comparison Room also gave two peaks cytidine retention temperatures (RT) 238° 250° 4 2/2% OV-11 100–200 mesh Supelcoport 1 m × mm I.D. glass column. Solvents had pronounced trimethylsilylation nucleosides. TMS compared acetonitrile found be best. When derivatized samples certain further diluted chromatographed an RWRR/P value observed. From this, it concluded that solubility primary factor incomplete derivatization these experiments. amount water 10 ppt, showed significant decrease RWRN/P values. Cytidine (RT RT 250°) presence 0.5 ppt water. peak used gas-liquid chromatographic analysis mixture nucleosides; thus has stability derivatives. 1% TMCS, non-solvent silylations, no differences