Checking The Photometer; Checking The Overall System - wtw photolab S12 Operating Instructions Manual

5 Analytical Quality Assurance (AQA)

5.2.1 Checking the Photometer

As soon as the photometer is activated it is running a Self-Check. This
means the hardware and the soft ware of the photometer is checked and
compared with internal standards.
As soon as the photometer is activated it is running a Self-Check. This
means the hardware and the soft ware of the photometer is checked and
compared with internal standards.
The photometer itself is checked in the AQA 1 mode with the
®
Spec tro quant Photo Check: the pack in cludes round cells con tain ing
stable test solu tions (secondary stan dards) for checking the photo meter
at the 445, 525, and 690 nm wave lengths. The test solutions are measured
in a refe rence photo me ter monitored with primary standards, and the
certificate stating the absorbance values is enclosed with the package
unit. These desired values with the per missible tolerances are entered into
the pho tometer or else handwritten into the control chart. For the meas-
ure ment the cell is placed in the compartment for the round cell and identi-
fied by the photometer via the bar code, and the measured absorbance is
com pared with the de sired value. The ab sorbance is shown on the display
and can be entered into the corresponding control chart.
The measurement of four cells for a given wavelength tests – in addition to
the wavelength accuracy – also the linearity of the absorbance over the
effective range.
The verification of the instrument, as it is required by DIN/ISO 9000 or
GLP, can be easily performed by using the Spec tro quant
The PhotoCheck hence offering the possibility to check the instrument. All
of the corresponding documentation, required by these certifi cation guide-
lines, is done by the photometer auto ma tically.

5.2.2 Checking the Overall System

Test for the overall system includes checking the working equipment and
checking the handling operations.
The overall system can be checked using standard solutions of a known
content, preferably with the Spectroquant
with the AQA 2 mode in the photometer.
®
Spectroquant CombiCheck are ready-to-use standard solutions that in
terms of the analyte concentration are finely adjusted to the individual test
kits. They contain a mixture of several analytes that do not interfere with
each other. The stan dard solution (R-1) is used in the same way as a
sample. A double determination is recommended as a measure to
diagnose any random errors.
Standard solutions for photometric applications (CRM) are ready-to-
use standard solutions that in terms of the analyte concentration are finely
adjusted to the individual test kits. The standard solution is used in the
same way as a sample. A double determination is recommended as a
measure to diagnose any random errors.
In addition to the CombiCheck and the standard solutions for photometric
applications, it is also possible to use CertiPUR
this checking procedure. These contain 1000 mg of the respective analyte
per liter of solution.
They can be diluted to different final con cen trations, which should prefer-
ably lie approxi mately in the middle of the mea sur ing range of the re spec-
tive test kit. The table presented in Appendix 2 pro vides an over-view of
the available CombiCheck and ready-to-use standard solu tions.
Release 01/2012
®
PhotoCheck.
®
CombiCheck; this corres ponds
®
stan dard solutions for
photoLab ® Series
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