Quality Control For The User - wtw PhotoLab S12-A Operating Instructions Manual

photoLab ® Series
5 Analytical Quality Assurance (AQA)

5.2 Quality Control for the User

Checking the
working equip-
ment
Pipette
Checking the
handling
operations
Influence of the sample
16
The certificate for the test kit, available for each lot produced, docu-
ments 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 ran-
ge; every measurement value can be affected by this deviation; this para-
meter is a measure for the accuracy.
Standard deviation for the procedure:
Measurement for the dispersion of the measurement values over the
entire measuring range, ex pressed in ± mg/l.
Coefficient of variation for the procedure:
Measurement for the dispersion of the measurement values over the enti-
re measuring range, ex pressed in %. The smaller the standard deviation/
coefficient of variation for the procedure, the more pronounced the linea-
rity of the calibration curve.
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 re gard, in the form of the different quality mode. The instru-
ment, or the whole system (includ ing reagents and all accessories) will be
checked, depending on which quality mode selected. All of checking ope-
rations can thus be supported by the pho tometer and the check values
accordingly docu mented as per GLP (Good Laboratory Practice) recom-
mendations (see Function description, "Analytical Quality Assurance").
The following diagram provides an overview regarding internal quality-
assurance aspects:
Test kit Photometer
Carefully pipette 3.0 ml
Suspend the bottom Heat the reaction cell in
of the sample into a
sediment in the cell by the thermoreactor at
reaction cell, close tight-
swirling. 148 °C for 2 hours.
ly with the screw cap,
and mix vigorously.
Caution, the cell
becomes very hot!
Test for recovery
Thermoreactor
Remove the reaction Swirl the cell after
cell from the thermo- 10 minutes.
reactor and place in a
test-tube rack to cool.
= Test for the
overall system
Release 01/2009