Fat is a lipid compound composed of glycerol (glycerol) and fatty acids, which can be used in fat-soluble organic solvents.
In this experiment, the fat was extracted with a fat-soluble solvent and weighed by evaporation to remove the solvent by evaporation. The entire extraction process is carried out in a Soxhlet extractor, and the fat-soluble solvent usually used is diethyl ether, or petroleum ether with a boiling point of 30C 60°C. In addition to fat, the fat-soluble substances extracted by this method also include free fatty acids, phosphoric acid, sterols, aromatic oils and some pigments, so they are called "crude fat". At the same time, the lipids (mainly lipoproteins) in the bound state of the sample cannot be directly extracted, so this method is also called the quantitative determination of free lipids.
Preparation: Heat the water temperature of the thermostatic water bath (80C) beforehand. Be sure to keep the inside of the extraction tube and flask dry. Clean;If not, wash it and dry it in a drying oven at 120°C. Fold the filter paper bucket: Take a piece of 011cm filter paper, fold it into a simple shape, and then fold one end of it and seal it to make a filter paper bucket.
Weighing: Peel several peanut kernels and thoroughly mash them with a hammer in a mortar as experimental samples. Referring to the experimental equipment and equipment D, weigh the filter paper bucket on the electronic balance, and then take 2 scoops (about 2g) of samples with a medicine spoon and load them into the filter paper bucket, and fold the opening of the filter paper bucket to seal itPrevent samples from escaping the filter paper bucket. Adjust the height of the filter bucket so that it is placed slightly below the upper elbow of the siphon when placed in the extraction tube. Place the filter paper bucket containing the sample on the electronic balance and weigh it, and the difference between the two masses is the mass of the sample.