利用顶空气相色谱测定纤维素衍生物中甲氧基和羟丙氧基含量  

Determination of Methoxyl and Hydroxypropoxyl Contents in Cellulose Derivatives by Headspace Gas Chromatography

作　　者：张亮亮[1] 付时雨[1] 谢传龙[1] 詹怀宇[1] 

机构地区：[1]华南理工大学制浆造纸工程国家重点实验室,广东广州510640

出　　处：《造纸科学与技术》2011年第3期75-79,共5页Paper Science & Technology

基　　金：国家973项目(No.2010BC732206);国家自然科学基金(No.30972324)

摘　　要：本文建立了一种顶空气相色谱法测定纤维素衍生物中甲氧基和羟丙氧基含量的方法。按照改进的蔡氏法(Zeisel),在顶空瓶中通过氢碘酸与羟丙基甲基纤维素反应,使甲氧基和羟丙氧基转化为碘甲烷和2-碘丙烷,反应结束后加碱液中和过量氢碘酸防止腐蚀进样器和色谱柱,随后顶空进样气相色谱分析。在反应时以甲苯为内标物,采用内标法测定碘甲烷和2-碘丙烷含量,从而计算得出羟丙基甲基纤维素甲氧基和羟丙氧基含量。文章还考察了平衡时间、反应温度和反应时间等对测定的影响。在合适条件下,测定的碘甲烷与甲苯峰面积比与碘甲烷浓度呈线性关系(r=0.9997,n=7);2-碘丙烷与甲苯峰面积比同2-碘丙烷的浓度也有线性关系(r=0.9995,n=7),样品测定结果与药典法一致。该方法操作简便,快速准确,可用于羟丙基甲基纤维素的质量控制。This study demonstrated a headspace gas chromatography（HS-GC） method to measure the methoxyl and hydroxypropoxyl contents in cellulose derivatives with toluene as internal standard.The procedure consists of reaction of hydroxypropyl methyl cellulose with 57wt% hydriodic acid in headspace sample vials by a modified Zeisel method and neutralizing the remaining hydroiodic acid with sodium hydroxide before the HS-GC performance,which can avoid the damage of the sample injection system and column.The reaction time,reaction temperature and equilibration time of sample had effect on determination.Under the optimal determining condition,the reference standard curves showed a good linear relationship（methoxyl r=0.9997;hydroxypropoxyl r=0.9995;n=7）.Results were comparable to those obtained by chemical titration.Compared with other methods based on Zeisel reaction,the present method is simple,rapid,and has equal or better precision.It is well suited for the quality control of hydroxypropyl methyl cellulose needed in pharmaceutical manufacture.

关 键 词：测定 顶空气相色谱 甲氧基 羟丙氧基 羟丙基甲基纤维素 

分 类 号：TS745[轻工技术与工程—制浆造纸工程]