Velp Scientifica
– UDK139 Operating Manual
10004762/B5
87
17 - Kjeldahl method to determine the protein content on liver patè
Procedure
1) Sample:
2g of sample weighed with an accuracy of
0.1mg after homogenizing by
suitable device.
2) Reagents for digestion:
for each sample add in the test tube:
2 catalyst tablets CM (code CT0006650)
12 ml concentrated sulphuric acid (96-98%)
shake gently the test tube with sample.
For samples having high fat content, use 15ml of acid and then 5ml of hydrogen
peroxide.
3) Digestion:
heat for 45 min at 420 °C.
4) Cooling:
let cool the test tubes to 50-60 °C.
5) Distillation-titration:
place in position the test tube with sample in the unit UDK
139.
factor: 6.25
reagents addition:
dilution water= 50ml
H
3
BO
3
= 30ml
NaOH= 50 ml
Titrant: HCl 0.2N
Distillation time= 4 min
Steam power= 100%
Press the button starting distillation cycle.
References:
AOAC, “Official methods of analysis”, method 981.10
274