Thermo Fisher Scientific Ion Selective Electrodes Sodium - Manual (Page 14)

Sodium Electrode Instruction Manual
12
persists and you are using an electrode pair, try the same routine with a working reference
electrode.
4.
If the problem persists, the reagent may be of poor quality, interference in the sample may
be present or the technique may be faulty. (See the
Standards and Reagents, Sample,
and
Technique
sections below.)
5.
If another electrode is not available for test purposes, or if the electrode in use is suspect,
review the instruction manual and be sure to:
- Clean and rinse the electrodes thoroughly.
- Prepare the electrode(s) properly.
- Use the proper filling solution.
- Adjust the pH and the ionic strength of the solution by the use of the proper ISA.
- Measure correctly and accurately.
- Review
TROUBLESHOOTING HINTS.
Standards and Reagents
Whenever problems arise with the measuring procedure that has been used successfully in the past,
be sure to check the standard and reagent solutions. If in doubt about the credibility of any of the
solutions, prepare them again. Errors may result from contamination of the ISA, incorrect dilution
of standards, poor quality distilled or deionized water, or a simple mathematical miscalculation.
Sample
Look for possible interference, complexing agents, or substances which could affect the response or
physically damage the sensing electrode (or the reference electrode) if the electrodes work perfectly
in the standard, but not in the sample.
Try to determine the composition of the samples prior to testing to eliminate a problem before it
starts. (See
Measuring Hints, Sample Requirements,
and
Interference.)
Technique
Be sure that the electrode's limit of detection has not been exceeded. Be sure that the analysis
method is clearly understood and is compatible with the sample.
Refer to the instruction manual. Reread sections on
General Preparation and Electrode
Characteristics
. If trouble still persists, please call Eutech Instruments Pte Ltd. at (65) 6778-6876
and ask for the Customer Services Department.