Purity of potassium hydrogen phthalate, determination with precision coulometric and volumetric titration--a comparison.
The mass fraction of potassium hydrogen phthalate (KHP) from a specific batch was certified as an acidimetric standard. Two different analytical methods on a metrological level were used to carry out certification analysis: precision constant current coulometric and volumetric titration with NaOH. It could be shown that with a commercial automatic titration system in combination with a reliable software for the end-point detection it is possible to produce equivalent results with the same accuracy in comparison to a definite method handled by a fundamental apparatus for traceable precision coulometry. Prerequisite for titrations are that a high number of single measurement are applied which are calibrated with a high precision certified reference material.
Recknagel
Sebastian
S
Federal Institute for Materials Research and Testing (BAM), Division of Inorganic-Chemical Analysis, Reference Materials, Richard-Willstaetter-Str. 11, D-12489 Berlin, Germany. sebastian.recknagel@bam.de
Breitenbach
Martin
M
Pautz
Joachim
J
Lück
Detlef
D