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(c) Determination of Crude Fat
Practical 1-Proximate composition analysis of feed ingredients and prepared feeds
(c) Determination of Crude Fat
Principle
Ether is continuously volatilized, condensed and allowed to pass through the sample resulting in extraction of ether soluble fractions. The extract is collected in an aluminum extraction cup. When the process is completed the ether is distilled and collected in other container and the remaining crude fat is dried and weighed.
Ether is continuously volatilized, condensed and allowed to pass through the sample resulting in extraction of ether soluble fractions. The extract is collected in an aluminum extraction cup. When the process is completed the ether is distilled and collected in other container and the remaining crude fat is dried and weighed.
Reagents and equipment
- Petroleum ether (b.p. 40-60°C),
- Thimbles and Extraction cups
- Soxhlet extraction apparatus.
- Dessicator
Method
Weigh 2-3 g of the dried sample (residue from dry matter determination can be used) into an extraction thimble. Place the thimble inside the Soxhlet apparatus. Connect a dry pre-weighed solvent flask beneath the apparatus and add the required quantity of solvent and connect to condenser. Adjust the heating rate to give a condensation rate of 2 to 3 drops/second and extract for 16 h. (The extraction time may be reduced to a minimum of six hour by increasing the condensation rate.) On completion, remove the thimble and reclaim the ether using the apparatus. Complete the removal of ether on a boiling bath and dry flask at 105°C for 30 min. Cool in a desiccator and weigh.
Weigh 2-3 g of the dried sample (residue from dry matter determination can be used) into an extraction thimble. Place the thimble inside the Soxhlet apparatus. Connect a dry pre-weighed solvent flask beneath the apparatus and add the required quantity of solvent and connect to condenser. Adjust the heating rate to give a condensation rate of 2 to 3 drops/second and extract for 16 h. (The extraction time may be reduced to a minimum of six hour by increasing the condensation rate.) On completion, remove the thimble and reclaim the ether using the apparatus. Complete the removal of ether on a boiling bath and dry flask at 105°C for 30 min. Cool in a desiccator and weigh.
Calculation
Last modified: Monday, 23 May 2011, 9:37 AM