干柱法测定牛奶中总脂肪含量

Determination of Total Fat in Milk by a Dry Column Method

报道了一种测定牛奶中总脂肪含量的快速干柱法。使用7.5cm×27mmi.d玻璃层析柱,以1.5gCelite545/CaHPO4·2H2O(9:1)为非脂成分捕集物,再将样品、无水Na2SO4、Celite545顺序研磨,装入柱中,用35mLCH2Cl2/CH3OH(9:1)进行洗脱,可在20min内洗脱完毕。测定了8种市售牛奶的脂肪含量,并与Roese-Gottlieb法进行了对比。结果表明,干柱法不仅操作简便、快速,而且对极性脂提取更完全。

A rapid dry column method for determination of total fat in milk was developed.A mixture of sample,anhydrous sodium sulfate and Celite 545 was packed above the Celite 545/CaHPO4·2H2O(9:1)trap in a glass chromatography column,and then the dry column was eluted with 35mL of solvent mixture of dichloromethane/methanol(9:1).The elution can be finished within 20min.The total fat contents of 8 kinds of milk samples were determined by the dry column method,the results were similar to those obtained by Roese Gottlieb method,but it was more complete to extract milk phospholipids by the dry column method.