13th WEEK

XIII.WEEK

13th WEEK

 QUALITATIVE ANALYSIS OF LIPIDS

 Explanation of qualitative observation principles

 Salkowski test, dichromate test

 Test observations and results report

Salkowski test

 Qualitative determination of cholesterol, a combination of steroids and alcohol.

 To dissolve the water-insoluble cholesterol, it must first be treated with organic solvents such as ether, chloroform, which can be dissolved. The method is based on the oxidation of cholesterol when treated with strong and concentrated acids such as sulfuric acid (H2SO4).

Oxidizing cholesterol forms a cherry-red color.

Salkowski test

 Cholesterol is a steroid derivative and consists of 4 interconnected hydrocarbon rings. The hydrocarbon ring steroid has hydrocarbon tail at one end and the hydroxyl group at the other end.

 To dissolve the water-insoluble cholesterol, it must first be

treated with organic solvents such as ether, chloroform, which

can be dissolved. The method is based on the oxidation of

cholesterol when treated with strong and concentrated acids

such as sulfuric acid (H2SO4). Oxidizing cholesterol forms a

cherry-red color.

Dichromat test



Qualitative determination of glycerol, a polar trihydroxy alcohol.



The method is based on the fact that chromic ions oxidize glycerol and

chromic ions are reduced to form a blue colored component. This test can

also be used to determine primary, secondary and reducing sugars.

 The students will be able to apply the knowledge acquired during the previous week.

 In this context, students will be organized

into groups of three before the study.

 Each group will be asked to perform salkowski and dichromate experiments.

 All consumables, chemicals, laboratory

equipment, especially glassware, and

machinery and equipment will be provided

as required.

 It will be reminded that each student will be responsible for the issues given to all other groups within the application.

 Students will be asked to report their

observations and results within the scope

of the application to the test report

immediately given to them at the end of

their applications.

 Students will be asked to remove any material they use, and if necessary, they will be expected to help with cleaning.

 Students will be allowed to leave after

laboratory safety and cleanliness is

ensured.