Separation and quantitation of mono-, di-, and triglycerides and free oleic acid using thin-layer chromatography with flame-ionization detection
Separation and quantitation of mono-, di-, and triglycerides and free oleic acid using thin-layer chromatography with flame-ionization detection
复制标题
使用薄层色谱法和火焰离子化检测器分离和定量甘油单酯、甘油二酯和甘油三酯以及游离油酸
作者：
G. Peyrou;V. Rakotondrazafy;Z. Mouloungui;A. Gaset
以缩水甘油和油酸为原料，在阴离子交换树脂存在下，通过缩水甘油的区域选择性开环反应制备了α-单油酸甘油酯。在反应过程中，脂肪化学合成培养基富含单油酸甘油酯，有效的乳化剂。该混合物可通过薄层色谱法与火焰离子化检测器（FID）联用进行分析。产品和试剂不需要衍生化。影响反应选择性的甘油二酯和甘油三酯副产物也可以使用该技术检测。胆固醇用作内标。考察了氢气流量、扫描速度、展开剂组成等因素对分离的影响。分离度对展开溶剂的己烷/乙醚比例高度敏感。采用己烷/乙醚/甲酸（体积比65：35：0.04）混合液，可以很好地分离甘油三酯、油酸、两种甘油二酯、胆固醇、α-单油酸甘油酯和缩水甘油。还检查了检测器响应、检测限和棒间变化。定义了一系列杆负载，其给出FID响应与负载的化合物量（相对于油酸和α-单油酸甘油酯）之间的直接关系。通过分析已知组成的油酸和α-单油酸甘油酯标准品的混合物来说明定量的准确度。
α‐Monoolein was prepared from glycidol and oleic acid by the regioselective opening of glycidol in the presence of an anionic resin. During the reaction, the lipochemical synthesis medium becomes enriched in monoolein, the effective emulsifying agent. This mixture can be analyzed by thinlayer chromatography coupled with flame‐ionization detection (FID). The products and reagents do not need to be derivatized. Diglyceride and triglyceride by‐products affecting the selectivity of the reaction also could be detected using this technique. Cholesterol was used as an internal standard. The factors influencing the separation, including the hydrogen flow rate, scan speed, and the composition of the developing solvent, were investigated. The degree of separation is highly sensitive to the hexane/diethyl ether ratio of the developing solvent. Good separation of triglyceride, oleic acid, the two diglycerides, cholesterol, α‐monoolein, and glycidol was obtained with the mixture hexane/diethyl ether/formic acid (65:35:0.04, by vol). Detector response, detection limits, and rod‐to‐rod variations also were examined. A range of rod loads giving a straightforward relationship between FID response and amount of compound loaded (relative to oleic acid and α‐monoolein) was defined. The accuracy of the quantification was illustrated by analysis of a mixture of oleic acid and α‐monoolein standards of known composition.