Preparation Of Standards - Thermo Scientific Star Series User Manual

Preparation of Standards

The standards should be prepared in the same ISE units as required by the sample
results . It is preferable to use serial dilutions with volumetric glassware to obtain
the different concentration levels .
Note: Any reagents such as ionic strength adjustors, should be added to
samples and standards as specified in the electrode user's guide or instruction
manual.
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The calibration points should bracket the expected concentration range of the
samples and there should be a tenfold change in concentration (i .e . 1 ppm and
10 ppm or 10 ppm and 100 ppm) .
Fresh aliquots of standard should be used at each calibration .
Thermo Scientific Orion Star Series Meter
™
ISE Technique
EN-43