Measure sodium - low range sodium, less than 500 ppm
SODIUM
One of the accepted methods for the
measurement of sodium is an electrode
method. The advantages of using a sodium
ion selective electrode are:
Interferences are eliminated by the use of the
single known addition process.
FPA 200
Tytronics’ FPA 200 is an on-line ISE
analyzer that measures sodium using an ion
selective electrode. The instrument uses a
batch sampling technique that allows the use
of 0.25” tubing for sample and reagent lines
so small amounts of solids will not affect
instrument performance. Other advantages
of batch sampling are:
Analytical results are not affected by
sample and reagent flows
Analyses are only performed as
frequently as required, minimizing
reagent consumption
ANALYSIS
The FPA 200 uses a known
addition measurement technique, which
provides more consistent results than a
direct electrode measurement. In the
instrument, 19 ml of sample is captured,
ammonium chloride diluted with de-ionized
water is added, and then an aliquot of
standard is added to the sample. From the
change in potential before and after the
addition, the original sample concentration is
determined.
METHOD
The advantage of the known addition
technique is that electrode drift will not
affect the instrument results. Electrode
slope is automatically determined by using a
standard of known concentration and
performing a single known addition on the
standard. Instrument accuracy is insured
through the use of the known addition
technique (SKA) and automatic slope
determination.
FEATURES:
Duplicates, on-line, the laboratory
method (ISE electrode)
Adds reagent to alleviate problems due to
sample pH fluctuations
Utilizes single known addition technique
so results are not affected by electrode
drift
Provides automatic slope calibration
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