Page 68 - Feed Lab

Estimation of Crude Protein - Kjelteck 2100 Distillation Method Suguna Management System Ver 1.0 / SOP / FQL / P2 - 04 Page 3 of 3

close the safety door. Dispense 60 ml of 40 % FFull chemical blanks and the recovery should
sodium hydroxide into the tube (Picture -19) be run before each and every batch of analysis
to compensate for any contribution from the
FOpen the steam valve and distill for 5 minutes (or reagents used.
collect 150 ml distillate, now the solution change
from wine red colour to green) (Picture -20) FFor blank, do all the points without sample. It
always should be zero titre value.
FAfter distillation, titrate the distillate with standard
0.2 N Hydrochloric acid until the wine red end point F For recovery, take 0.1gm urea AR and do same
appears. (Picture -21) digestion as per crude protein. It should be
100% ± 1% (urea AR nitrogen is 46.62%).

Picture-14 Picture-15 Picture-18 Picture-19

Picture- 20 Picture- 21
Picture-16 Picture-17
Note:
We can also use sodium sulphate instead of potassium sulphate. In such case, we should take 5 gram of sodium
sulphate and 0.5 gram of cupric sulphate.

CALCULATION
TV - Blank X N.of Hcl X1.401 X6.25
Crude Protein % = -----------------------------------------------------------------
Sample weight, g

REFERENCE
1.Bureau of Indian Standard IS 7874 1975
2. Association of Official Analytical Chemist 2000.

Prepared by : Approved by :
56 Director - Technical