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Idiomas disponibles
INSTRUCTION MANUAL CODE 80188 REV E
Common protein factors
Almonds
Nuts
Nut- peanuts
Jello
Soya
Barley, trenches, rye
wheat, whole flour
Flours (not whole one)
Rice
Corn
General
Saved
Milk and milky products
J
.P. SELECTA s.a.u.
Jun/2018
•
Insert the sample tube. See 5.1
•
Select mode «MANUAL» or «AUTOMATIC» and initiate the sequence.
•
Wait for the end of distillation. Buzzer sound.
•
Empty the sample tube.
•
Open the safety door.
•
Remove the sample tube. See 5.2
•
The unit is completely prepared to analyse the following sample. Any operation
of cleaning is needed, unless any malfunction has occurred during the analysis.
Visual Checking during the analysis:
Some visual checking can be applied from the colour that takes the solution on the
collector or in the sample tube.
This checking is useful at the beginning to set the optimal parameters or to solve
unit malfunctions.
Visual Checking on the sample tube: (Using CuSO
When the NaOH volume is sufficient, the sample becomes blue. (If not, program
more NaOH on the following a analysis)
Visual Checking on the collector:
The initial colour must be the fixative solution colour (Violet with mixed indicator
or Red with mixed indicator 5). If it is grey or green, it is because of not neutral-
ized rests of the previous sample remains on the collector. On this case stop the
analysis and run a cleaning operation. See 6.2
6.4 Analysis interruption
Press «STOP» to abort the analysis.
Note: The analysis interruption, left on the unit rests not neutralized that will cor-
rupts the following analysis. Run a cleaning operation (See 6.2) before to run new
analysis.
6.5 Titration and Protein contents (%) calculation
Prepare the titration burette with the reagent usually HCl 0.25N.
Slowly dispense the HCl 0.25N on the Erlenmeyer stirring it at the same time.
Titrate until the colour changes (end point at pH 4.65).
From the HCl volume (ml) consumption on the titration, the Kjeldahl Nitrogen (mg)
is calculated:
Nitrogen (mg) = 14 x Volume
5,18
5,30
5,41
And, from the nitrogen we calculate the sample protein content:
5,55
5,71
5.83
5,83
5,70
5,95
6,25
6,25
6,31
P2: Nitrogen (mg).
6,38
P0: Sample weight (mg).
F: Protein factor.
Autovía A-2 Km 585.1 Abrera 08630 (Barcelona) España
e-mail: [email protected] - website: http://www.jpselecta.es
(It can be modified without notice)
(ml) x Normality
HCl
P
2
% Protein =
x 100 x F
P
0
Page: 42
Catalyst)
4
HCl
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