Sample Requirements - Thermo Scientific 9101BN User Manual

Sample Requirements

Electrodes with an epoxy body should only be used in aqueous
solutions.
Electrodes with a glass body may be used in non-aqueous
solutions and solutions that contain organic solvents. A
minimum of 20% water must be present in the sample for the
best measurement results. Visit www.thermo.com/water to
download Dr. Martin S. Frant's article "How to Measure pH in
Mixed and Nonaqueous Solutions" and for additional information
on non-aqueous pH measurements.
The refillable Ag/AgCl electrodes contain a silver/silver chloride
(Ag/AgCl) reference that may become clogged in solutions
that contain silver complexing or binding agents such as TRIS,
proteins and sulfides. Frequent cleaning may be required when
measuring solutions that contain these agents. Proteins cause
the additional problem of coating the sensing bulb, so extra care
should be taken to keep the electrode clean while measuring
samples that contain proteins.
Refillable Ag/AgCl pH Electrode User Guide
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