title: Purity of potassium hydrogen phthalate, determination with precision coulometric and volumetric titration--a comparison.
abstract: 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.
authors.affiliation: 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
authors.forename: Sebastian
authors.initials: S
authors.lastname: Recknagel
authors.forename: Martin
authors.initials: M
authors.lastname: Breitenbach
authors.forename: Joachim
authors.initials: J
authors.lastname: Pautz
authors.forename: Detlef
authors.initials: D
authors.lastname: Lück