【作者】 张锦阳；

【导师】 曹玉华； 齐丽云；

【作者基本信息】 江南大学 ， 分析化学， 2009， 硕士

【摘要】 α-长链烷基甜菜碱(α-LAB)是一类以天然脂肪酸为原料开发得到的新型两性表面活性剂。本文建立了该表面活性剂及其合成过程中原料、主要副产物的定量分析方法,并考察了两种分析方法的适用条件以及影响因素。采用海明容量滴定法测定α-氯代十二酸(α-HDA)、十二酸(DA)和α-氯代十二酸(α-CDA)的的总含量;建立HPLC方法测定α-癸基甜菜碱(α-CB)、未反应原料DA和α-CDA、主要副产物α-HDA的含量。主要得到以下结论:建立了海明容量法标定磷钨酸溶液浓度,该方法快速准确,RSD小于0.3%,测定结果与联苯胺重量法一致,因此可以取代联苯胺重量法标定磷钨酸。通过海明返滴定方法可以准确测定除去三甲胺后α-CB产品中活性物的含量,α-CB平均回收率为100.33%。α-癸基甜菜碱产品中残留脂肪酸(包括α-CDA、α-HDA和DA)总含量可用溴甲酚绿两相滴定法直接测定,实验发现:当样品溶液中氯化钠浓度小于5 g/L、α-CB的浓度小于20 g/L时,分析结果准确,DA的回收率为98-100%,体系中的三甲胺对滴定结果无明显影响,因此产品可以直接用于分析。采用蒸发光散射检测器(ELSD),运用高效液相色谱,同时分析检测α-癸基甜菜碱产品组成。分析条件为:C18色谱柱(4.6 mm×250 mm,5μm),流动相为乙腈-甲醇-水的体积比为40.9:46.6:12.5(0.5%甲酸),流速为0.8 mL/min。该方法可以对α-癸基甜菜碱合成产品中的主产物α-癸基甜菜碱(α-CB)、副产物α-羟基十二酸(α-HDA)、未反应原料十二酸(DA)和α-氯代十二酸(α-CDA)进行良好分离和定量分析。该方法结果准确、灵敏度高,可作为其他方法的参照标准。选择合适的流动相,实现了用HPLC-RID方法对α-CB准确定量分析,α-CB在1.6-32μg内呈现出良好的线性关系,检测限为1.2μg。由混合脂肪酸合成得到的产品含有不同碳链的α-LAB,通过计算机辅助优化HPLC-ELSD方法,并经实验验证得到较满意的分离线性梯度洗脱的条件。这为分析混合α-LAB产品定量分析提供了色谱条件。更多还原

【Abstract】 By the analysis of a novel type of amphoteric surfactants alpha-long chain alkyl betaine(α-LAB) prepared through ammonolysis of long chain fatty acid derivative alpha-chlorododecanoic acid with trimethylamine,the chemical methods to determine alpha-capric betaine and free fatty acids were developed.A method for the determination of alpha-capric betaine(α-CB),alpha-hydroxy dodecanoic acid(α-HDA),dodecanoic acid(DA) and alpha-chlorinated dodecanoic acid(α-CDA) by high performance liquid chromatography (HPLC) coupled with evaporative light-scattering detection(ELSD) and refractive index detector(RID) was developed,and the effect was investigated.The main points were as follows:A novel rapid method for the standardization of phosphotungstic acid was developed by titration,the relative standard deviation is lower than 0.3%,and the result was consistent with the gravimetric analysis by Benzidine.A method to determine theα-LAB by back titration with Hamming was developed;the average recovery rate ofα-CB is 100.33%.A method to determine the free fatty acids by in reaction products was developed by two-phase titration with bromocresol green indicator,and the scope of application was the concentration of NaCl andα-CB in sample solution must be lower than 5 g/L and 20 g/L, respectively.The average recovery rate of DA is 98-100%;the relative standard deviation is lower than 0.3%.There is no influence of trim ethyl amine in product for the result,so this method can determine free fatty acids directly.A new method of HPLC-ELSD has been developed for the separation and quantitative analysis of the compose of alpha-capric betaine.This method employs an isocratic elution, mobile phase was composed of acetonitrile,methyl,water(V:V:V=40.9:46.6:12.5) and the flow of mobile phase was maintained at 0.8 mL/min.The separation and quantitative of alpha-capric betaine,alpha-hydroxy dodecanoic acid,alpha-chlorinated dodecanoic acid, dodecanoic acid were performed.This method has a high accuracy and sensitivity,so it can be the standards for other methods.A high-performance liquid chromatography technique with refractive index detector has been developed for the determination ofα-CB by the change of mobile phase.The minimum limit of detection ofα-CB is about 1.2μg and ratio of mass to signal is essentially linear in the range of 1.6 to 32μg.A method for the separation analysis of a mixture ofα-LAB prepared by fatty acid mixed was developed by computer-aided optimize and experimentation.The method provides an analytical condition for quantitative analysis of the mixture ofα-LAB.更多还原