Thermo Fisher Scientific Ion Selective Electrodes Iodide User Manual

Page 14

Instruction Manual

Iodide Electrode

persists and you are using an electrode pair, try the same routine with a working reference
electrode.

If the problem persists, the standards and/or reagents may be of poor quality, interferences
in the sample may be present or the technique may be faulty. (See

Standards and

Reagents, Sample,

and

Technique

sections below.)

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 electrodes 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/deionized water, or a simple mathematical miscalculation.

Sample

Look for possible interferences, complexing agents, or substances which could affect the response
or physically damage the sensing electrode (or 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

Interferences

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 again. Reread sections on

GENERAL PREPARATION

and

ELECTRODE CHARACTERISTICS.

If trouble still persists, call Eutech Instruments Pte Ltd. at (65) 6778-6876 and ask for the Customer
Services Department.