Question

3. Soxhlet extraction method was applied to a solid food sample that matrix effects are expected to be significant for the total lipid analysis (Figure 2). The sample was directly subjected for extraction, and ethanol was used as the extraction solvent. А B с D Figure 2. Soxhlet apparatus (a) Identify A, B, C and D. (b) Itemize the procedures for Soxhlet extraction method. Explain why each of the procedures may be necessary (c) Calculate the percent lipid of the sample if the results are as following: Food sample 12.5755 g Initial weight of the solvent flask 30.5697 g Weight of the solvent flask treated with ethanol 30.6271 g Weight of the solvent flask treated with sample 34.0293 g [Answer: 27.51% . .

Answer 1

a)A- Condenser

B- Extraction Chamber of the Soxhlet Extractor

C-Thimble

D-Round Bottomed flask or Boiling Flask

b)The Soxhlet Extraction is a Solid Liquid Continous extraction method.The solvent is place in the boiing flask and the solid sample is paced in the thimble of the Soxhlet Extractor.The solvent is heated and gets vapourized,and cooled by using a condenser equipment,which now fills the thimble of the extractor.The excess solvent gets back into the boiling flask through the siphon arm.This process gets continued until the required component present in the solid sample gets extracted into the organic solvent.

c) The solution is as follows:

Given weight of He sample : 12.575.59M). Weight of RB Flask with solvent - 30.6271gm. So weight of sample that is extracted into weight of. RB Flask with sample: 34.02939m (23) the solvent is Wz - Wt. of RB Flast 34.0293- 30.5697 3. 45969m 7. of lipid present in the sample is: = 3.4596 12.5755% 2% Too a 3.4596x 100 12.5755 27.51 27.51% of lipids are present in sample