Flor R V, Prager M J
J Assoc Off Anal Chem. 1980 Jan;63(1):22-6.
Total lipids were extracted from food products by heating the sample under total reflux for 15 hr with a mixture of chloroform--methanol (70 + 30) in the ratio 6.67 mL solvent/g sample. The solution was filtered and evaporated, and the lipids wer dissolved in petroleum ether, filtered, and evaporated to yield the crude lipids and surfactants. The purified lipids are suitable for butterfat determination directly, or are readily separated from the surfactants by alumina chromatography. The method is particularly suited to the milk products studied, which produced troublesome emulsions if aqueous treatments were used. The method also allows ready extraction of total fats from drained feta cheeses, whereas Soxhlet extraction with petroleum ether sometimes fails. The effects of reflux time and varying ratios of chloroform to methanol were studied.
通过将样品与氯仿 - 甲醇（70 + 30）的混合物按6.67 mL溶剂/g样品的比例在全回流下加热15小时，从食品中提取总脂质。将溶液过滤并蒸发，脂质溶解在石油醚中，过滤并蒸发以得到粗脂质和表面活性剂。纯化的脂质适合直接用于测定乳脂肪，或者通过氧化铝色谱法很容易地与表面活性剂分离。该方法特别适用于所研究的乳制品，如果使用水相处理会产生麻烦的乳液。该方法还能从沥干的羊乳酪中轻松提取总脂肪，而用石油醚进行索氏提取有时会失败。研究了回流时间以及氯仿与甲醇不同比例的影响。
