XII
The
certificate for the test kit,
available for each lot
produced, documents the quality of the reagents
contained in the test kit.
Calibration function:
The calculated function must agree, within specified tolerances,
with the function electronically stored in the photometer.
Confidence interval:
Maximum deviation from the desired value over the entire mea-
suring range; every measurement value can be affected by this
deviation; this parameter is a measure for the accuracy.
Standard deviation for the procedure:
Measurement for the dispersion of the measurement values over
the entire measuring range, expressed in ± mg/l.
Coefficient of variation for the procedure:
Measurement for the dispersion of the measurement values over
the entire measuring range, expressed in %. The smaller the stan-
dard deviation/coefficient of variation for the procedure, the more
pronounced the linearity of the calibration curve.
5. Analytical Quality Assurance (AQA)
A complete check comprises the entire system, i.e.
the working equipment and the mode of operation.
The photometer offers an optimum degree of support
in this regard, in the form of the different quality
mode. The instrument, or the whole system (includ-
ing reagents and all accessories) will be checked,
depending on which quality mode selected. All of
checking operations can thus be supported by the
photometer and the check values accordingly docu-
mented as per GLP (Good Laboratory Practice)
recommendations (see Function description, “Analy-
tical Quality Assurance”).
The following diagram provides an overview
regarding internal quality-assurance aspects:
5.2 Quality Control for the User
= Test for the
overall system
Mischen
Küvette wird heiß,
am Verschluß
anfassen
2 ml Probelösung
in ein Reaktions-
küvette geben
im Thermoreaktor
erhitzen
148° C, 120 min
mind. 10 min
abkühlen
Abkühlen auf
Raumtemperatur
(mind. 30 min)
Mischen
Messen
C2/25 • CSB 1500 • Chemischer Sauerstof
fbedarf
Meßbereich 100 • 1500 mg/l CSB
14 mm
1
4
.
7
2
5
8
0
3
6
9
C
Checking the
working
equipment
Pipette
Test kit
Photometer
Thermoreactor
Checking the
handling operations
Influence of the sample
Test for recovery
Carefully
pipette 3 ml of
the sample into a reaction
cell, close tightly with the
screw cap and mix
vigorously.
Caution, the
cell becomes very hot!
Suspend the bottom
sediment in the cell by
swirling.
Heat the reaction cell in
eactor at
148
°
C for 2 hours.
Remove the reaction
cell fr
-
r
cell rack to cool.
Swirl the cell after
10 minutes.
Release 07/03
