羟乙基淀粉的羟乙基取代位置的研究

将羟乙基淀粉进行甲基化-水解-还原乙酰化反应，产生羟乙基葡萄糖的部分甲基化糖醇乙酸酯衍生物，应用气相色谱/化学电离质谱（GC/CIMS）和气相色谱/电子轰击质谱/质谱（GC/EIMS/MS）联用技术研究了羟乙基在淀粉糖环上的取代位置，发现G-2位取代的量是总取代量的82.0％。

The Position Investigation of the Substituted Hydroxyethyl Groups of Hydroxyethyl Starch

Hydroxyethyl starch (HES) is currently finding increasing use as a replacement for plasma. It is desirable to have a precise knowledge of the positions and the categories of the substituted hydroxyethyl groups in clinical applications, as it affects the pharmacokinetics and pharmacology. The study of the positions of the substituted hydroxyethyl groups involves the conversion of all free hydroxyls in the original HES into methoxyl groups, followed by hydrolytic cleavage of the glycosidic linkages with acid and the conversion of methylated sugar into alditol acetates. The derivatives have been studied by gas chromatography/chemical ionization mass spectrometry (GC/CIMS) and GC/electron impact mass spectrometry (EIMS)/MS. Investigations concerning the EI fragmentation schemes allowed secure determinations of the positions and the categories of the substituted hydroxyethyl groups, especially determinations of monohydroxyethyl derivatives and their differentiations in the EI fragmentation schemes. CI measurements permitted the recognition of introduced hydroxyethyl groups in the glucose residues by detection of (M+1) +-60 signals. Proposed generations of the main fragment ions are presented. According to the relative peak areas of the signals in the total ion chromatogram, the quantity of substitution is 36.5% and the ratio of the substition at C-2 is 82.0%.