Lipid transmethylation methods described in the literature are not always evaluated with care so to insure that the methods are effective, especially on food matrix or biological samples containing polyunsaturated fatty acid (PUFA). The aim of the present study was to select a method suitable for all lipid species rich in long chain n-3 PUFA. Three published methods were adapted and applied on individual lipid classes. Lipid (trans)methylation efficiency was characterized in terms of reaction yield and gas chromatography (GC) analysis. The acid-catalyzed method was unable to convert triglycerides and sterol esters, while the method using an incubation at a moderate temperature was ineffective on phospholipids and sterol esters. On the whole only the method using sodium methoxide and sulfuric acid was effective on lipid classes taken individually or in a complex medium. This study highlighted the use of an appropriate (trans)methylation method for insuring an accurate fatty acid composition.

文献中描述的脂质转甲基化方法并非总是谨慎评估，以确保该方法有效，尤其是在食品基质或含有多不饱和脂肪酸（PUFA）的生物样品上。本研究的目的是选择一种适用于所有富含长链n-3 PUFA的脂质物种的方法。修改了三种公开的方法并将其应用于单个脂质类别。根据反应产率和气相色谱法（GC）分析表征脂质（反式）甲基化效率。酸催化方法不能转化甘油三酸酯和固醇酯，而在中等温度下使用温育的方法对磷脂和固醇酯无效。总体而言，仅使用甲醇钠和硫酸的方法对单独或在复杂培养基中摄取的脂质类别有效。这项研究强调了使用适当的（反式）甲基化方法来确保准确的脂肪酸组成。