Hach-Lange DR 5000 brewerie analysis, supplementary software LZV570 - Manual (Page 13)

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Working procedures
8. Blank value
a. Introduce 10 ml sample (expel carbon dioxide from beer by
shaking; clarify turbid wort or beer by centrifuging) into a
25 ml measuring flask.
b. Add 8 ml CMC-EDTA solution and mix thoroughly.
c. Add 0.5 ml dilute ammonia solution and mix thoroughly.
d. Make up to 25 ml with H
2
O and mix again.
Note: Mix thoroughly after adding each individual solution
Result
The result is expressed in mg/l without any decimal places.
Accuracy
SD = ± 9
Standard values
Beer: 150–200 mg/l
Literature
MEBAK Brautechnische Analysenmethoden
4th Edition 2002, Volume II, pp 107ff
2.2.1 Procedure for measuring total polyphenols
1. Prepare samples and blank value solutions as described in the
working procedure.
2. Select STORED PROGRAMS in the “Main Menu”. Select test
number 802 .
3. Insert blank value cuvette (see sample preparation) into the cell
compartment. Close the cell compartment. Touch ZERO .
4. Insert the sample cuvette containing the prepared sample into
the cell compartment and close the cell compartment. Touch
READ . The result is displayed.
Note: Analysis of additional samples: Repeat working procedure from
point 3. In other words, each sample has to have its own specific blank
value solution.