The calibration of glass electrodes and cadmium and copper ion-selective electrodes

✍ Scribed by Ingrid Aggeryd; Yi-Chang Liang; ůAke Olin

• Publisher: Elsevier Science
• Year: 1985
• Tongue: English
• Weight: 393 KB
• Volume: 169
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/s0003-2670(00)86225-x

✦ Synopsis

The glass electrode is calibrated on the concentration scale against the hydrogen electrode from measurements of the potentials of the two electrodes immersed in the same buffer. The p[H+] of the buffer is changed between 2 and 11 by addition of base. The difference in potential between the electrodes is used to correct the glass electrode potentials. Analogously, cadmium and copper ion-selective electrodes (i.s.e.) can be calibrated against the corresponding metal-amalgam electrodes in p[M'+] buffers. The response of the copper i.s.e. (Radiometer Selectrode) was always close to Nernstian, whereas the response of the cadmium i.s.e. was variable and larger than Nernstian. The method is independent of errors in equilibrium constants and composition of the buffers, but it assumes ideal behaviour of the hydrogen and amalgam electrodes.