气质联用法和MALDI-TOF-MS测定羟丙基-β-环糊精平均取代度
Determination of Average Degree of Substitution of Hydroxypropyl-β-cyclodextrin by Gas Chromatography Mass Spectrometry and MALDI-TOF-MS

为建立气质联用（GC-MS）和基质辅助激光电离-飞行时间质谱（MALDI-TOF-MS）测定羟丙基-β-环糊精（HP-β-CD）平均取代度的方法。对HP-β-CD先进行甲基化反应，后将其酸水解为单环葡萄糖单元，通过硼氢化钠还原成链状葡萄糖单元，经羟基乙酰化后，进行气质联用分析，计算平均取代度（DS），并与MALDI-TOF-MS测定的结果进行比较。结果表明：利用GC-MS分析测得的DS为7.0，略高于使用MALDI-TOF-MS测得结果（DS=6.6）。GC-MS分析方法灵敏度较高，但是前处理步骤较为繁杂，MALDI-TOF-MS法能够快速检测样品，2种方法均可提供相关分析方法依据。
GC-MS and matrix-assisted laser desprption-ionization time of flight mass spectro (MALDI-TOF-MS) metry were established to measure degree of substitution of hydroxypropyl-β-cyclodextrin. Hydroxypropyl-β-cyclodextrin methylation reaction, then were decomposed into acid hydrolysis monocyclic glucose units by sodium borohydride reduction into chains of glucose units, after hydroxyl acetylation of GC-MS, we calculated the average degree of substitution. We compared it with those gained from the method of MALDI-TOF-MS.The average degree of substitution was 7.0 which was examined by GC-MS,slightly higher than MALDI-TOF-MS with measured results (DS=6.6).GC-MS analysis had high sensitivity, but the pre-treatment step was more complicated. MALDI-TOF-MS detected the sample rapidly, both methods were available to measure the degree of substitution of hydroxypropyl-β-cyclodextrin which can provide a basis for correlation analysis.