Automated high precision secondary pH measurements

Autor:	Beatrice Adel, P. T. Jakobsen, B. Seidl, C. E. Wied, F. Stefan, R. Kawiecki, A. Kauert, Frank Bastkowski, H. B. Kristensen, H. D. Jensen, R. Eberhardt, P. Spitzer
Rok vydání:	2013
Předmět:	Accuracy and precision Temperature control Materials science Reference measurement law Calibration Analytical chemistry Measurement uncertainty Standard uncertainty Ph measurement Instrumentation Glass electrode law.invention
Zdroj:	Review of Scientific Instruments. 84:045105
ISSN:	1089-7623 0034-6748
DOI:	10.1063/1.4798644
Popis:	A new setup for high precision, automated secondary pH measurements together with a reference measurement procedure has been developed and tested in interlaboratory comparisons using buffers pH 4.005, pH 7.000, and pH 10.012 at 25 °C and 37 °C. Using primary buffers as standards, a standard uncertainty in pH better than 0.005 can be reached. The central measuring device is a one piece, thermostatted cell of PFA (perfluoroalkoxy) with a built-in Hamilton(®) Single Pore™ Glass electrode. Due to its flow-through principle this device allows pH measurements with low consumption of measurement solutions. The very hydrophobic and smooth PFA as construction material facilitates complete emptying of the cell. Furthermore, the tempering unit affords very precise temperature control and hence contributes to the low target uncertainty of the produced secondary buffer solutions. Use of a symmetric measurement sequence and the two point calibration was sufficient to reach high precision and accuracy.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::221d2b902865358713bc7971776cbd5d https://doi.org/10.1063/1.4798644 Zobrazit plný text záznamu