Take 5ml of chloroform and 5ml of Huble’s iodine reagent in a beaker which will give pink colour to the solution. Solubility test is the preliminary test which detects the presence of all lipids. Acrolein Test, Unsaturation Test, Test for Phosphate, Emulsification Test, Lieberman Burchard Test, Carr Price Reaxtion and Modified Furter Meyer Test The pink colour will be discharged indicating the presence of free fatty acids. Oil or liquid fat becomes finely divided and is dispersed in water when shaken with water to form emulsification. Emulsification test is used to detect the presence of lipids. Then add 1-2 drops of Sudan IV to the solution. This process is called saponification. Take 1 ml of the oil in a test tube and add an equal amount of alcoholic KOH solution, mix them thoroughly and keep the mixture during the course of warming and shake up gently with a little distilled water. against the blank tube and plot these against the amount of cholesterol. This test is also given by reducing sugars, so before confirming glycerol be sure that the reducing sugars are not present. are fat-soluble. This is carried in the follow­ing way. You will need 6 large and 6 small test tubes containing the four test lipids as outlined in the table on the Report Sheet. Take pure glycerol in a dry test tube; add to it a few crystals of potassium hydrogen sulphate. If the aliphatic chain contains no double bond then it is called saturated and if it contains one or more double bond it is called unsaturated. Add 10 drops of acetic anhydride in a solution and then 2-3 drops of concentrated sulphuric acid. Esters can be hydrolysed by alkali to yield the parent alcohol and salt. Add 10 ml of chloroform and then 25 ml of the pyridine sulphate di-bromide reagent. wear safety goggles; ethanol is flammable; avoid contact with skin and eyes Observation: Observe the tube for the appearance of red-orange colour to the solution. PROCEDURE Part 1. Warm gently to mix and then heat strongly. Hazards. Emulsifying agents emulsify the lipid by which the lipid appears as the tiny droplets suspended in the solution. What are the general characters of bryophytes? mark to test tube 1. Part A. Solubility of Some Lipids. Then the chromic ions oxidize the glycerol and are reduced to chromous ions in the presence of nitric acid giving a blue colour to the solution. The emulsion test is an alternative test for lipids. Take 1ml of the lipid sample in a test tube. The chromic ions oxidize the glycerol and in this process they are reduced to chromous ions which give the blue colour. Principle: Emulsification is the process which stabilizes the water and oil emulsion, by the help of emulsifying agents. As Sudan IV is a non-polar stain, therefore the lipid will bind with it and retain the colour of the stain and gives a red-orange colour. You will also test several lipids with bromine to determine the degree of unsaturation of the lipid. Positive result: If glycerol present in the sample it will give a pungent smell. Negative result: Lipids are insoluble in a polar solvent i.e. Palmitic has 16 carbon atoms and stearic has 18 carbon atoms. Shake gently. Negative result: If glycerol is absent in a sample, then it will not produce a pungent smell. HNO3, mix well and note that the brown colour is changed to blue. Positive result: If the colour of the solution changes from brown to blue, then it indicates the presence of glycerol. There are several methods which are used for the qualitative analysis of lipids and its components. The presence of lipids in the qualitative analysis is measured by the colour change. Then dissolve it in some water and add alkaline phenolphthalein solution and shake. Tests for unsaturation of fatty acids: Unsaturated fatty acids like oleic acid can react with halogens like bromine and iodine due to presence of double bonds as shown below. Now we will consider some qualitative and quantitative tests for lipids. The number of drops determines the taking up of iodine by the unsaturated fatty acid of lipids. Derived lipids include fatty acids, glycerol, steroids, other alcohols, fatty aldehydes, and ketone bodies, lipid soluble vitamins, and hormones. Lipoproteins are com­binations of lipids with proteins. Oils and fats usually contain long chain fatty acids and are, therefore, the starting materials for the preparation of soap. Measure the absorbencies at 625 m|a. The upper layer turns red and the sulphuric acid layer shows a yellow colour with a green fluorescence.