Post on 11-Jan-2016
description
08.2005 BK
Traceable pH measurements and GLP compliant documentation
Sartorius DocuClip & DocuMeterpH
The new standard for reliability in electrochemical analysis
08.2005 BK
Traceable pH measurements and GLP compliant documentation
pH measurement: Generating and documenting data
Evaluation of signals
pH electrodes 1, 2, 3, ...
Transmission of measuring signal
pH meter
Origin of measuring signal
Display of cal-culated pH value
The way how to evaluate the signal is called calibration or standardization
This procedure is stored in the meter and will be used with all other electrodes until a new calibration has been taken
08.2005 BK
Traceable pH measurements and GLP compliant documentation
pH measurement: gaps in documentationExamples of GLP-compliant documentation today
------------------------ SARTORIUSStd. data13-12-2004 13:48:31Model PP-25Serial No. 12143916------------------------Channel A: pH modeStd interval off 4.01 pH 13-12-2004 13:48:3198.79% (58.45 mV/pH) 7.00 pH 13-12-2004 13:47:09Standardization ok.Name:
Documentation of equipment : meter model: meter serial number,: meter software version: date / time of standardization and measurements
What about the electrode?
No documentation : of electrode serial number : that calibration base and measured value have been evaluated with the identical electrode
but
08.2005 BK
Traceable pH measurements and GLP compliant documentation
What is needed to complete the documentation of a pH system?
Evaluation of signals
Transmission of raw measuring signal
pH meter
Origin of measuring signal
Display of cal-culated pH value
Sending back the information how to evaluate the raw signal
Sending this information back to the meter …
along with ID information
Storing this specific infor-mation in the individual electrode and
08.2005 BK
Traceable pH measurements and GLP compliant documentation
The expected solution: An electrode with built-in memory
Problems— An electrode with built-in memory chip needs a special data cable and a special plug and socket
— Standard electrodes cannot be used with such a pH meter
— There is no flexibility in choice of electrode manufacturer or type
— For new electrode types new SOPs or even new validations are needed
— Higher electrode costs
08.2005 BK
Traceable pH measurements and GLP compliant documentation
The new Sartorius approachA memory attached to the electrode cable
— Memory physically fixed at the cable
— Non detachable
— Stores calibration data, serial no., calibration history
— Makes any electrode smart
— Belonging DocuMeter also works with common electrodes
DocuClip
08.2005 BK
Traceable pH measurements and GLP compliant documentation
Documeter and Docuclip: gaps in documentation closedGLP-compliant documentation
: model and serial number of electrodes: nominal buffer values: raw signal of standardization (mV): initial standardization: standardization history: relation of measured values to the underlying standardization
Documentation now includes
08.2005 BK
Traceable pH measurements and GLP compliant documentation
pH measurement: gaps in documentation closedExamples of GLP-compliant documentation today
Documentation of equipment and electrode
including: model ID and serial number: date and time of standardi- zation and measurement: measured value is related to the underlying standardization data
08.2005 BK
Traceable pH measurements and GLP compliant documentation
DocuMeter & DocuClipDocuClip initially calibrated at the manfacturer‘s site
DocuMeterpH and PY-P…doc
Automatic electrode recognition incl. type, order no. and serial number as well as the device used for the initial calibration
Measuring results are based on data transferred from the Clip
Disconnecting the DocuClip causes the meter to calculate the pH based on theoretical Nernst factor (59,16 mV/pH at 25°C)
Electrode type pH: PY-P12
Serial NumberA044805026
Model f. Cal.Cal.Ser:
device9876543210
OK
08.2005 BK
Traceable pH measurements and GLP compliant documentation
DocuMeter & DocuClipDocuClip using any elctrode
DocuMeterpH and blank DocuClip
Recognition of the DocuClip and its status
Automatically starting the initializing routine
Storing identification data and initial calibration data as „Initial Calibration“ for the whole life cycle of the electrode
Storage of four additional calibration data sets in the DocuClip
Any further calibration overwrites the oldest data set
Initial Calibration
Input Serial No.
Cancel Start
Initial Calibration
Programming DocuClip
08.2005 BK
Traceable pH measurements and GLP compliant documentation
Initial Calibration
Electrode No.
O O O O O O 0
Cancel
<
>
6 digits can be stored in a blank DocuClip
DocuMeter & DocuClipDocuClip using any elctrode
>
<
Cancel
1 3 5 7 9 1O
Electrode No.
Initial Calibration
DocuClip electrode no. 135791
is pH electrode … (original serial no.) / … (manufacturer) / … (model or order no.)
Entry in a lab journal For cross-reference necessary:
… results in gap-less tracebility!