Needle-like IrO/Ag combined pH microelectrode

作者：Zimer Alexsandro M; Lemos Sherlan G; Pocrifka Leandro A; Mascaro Lucia H; Pereira Ernesto C^*

来源：Electrochemistry Communications, 2010, 12(12): 1703-1705.

DOI：10.1016/j.elecom.2010.10.001

• Combined pH microelectrode
• Iridium oxide
• Polymeric precursor method

In this study, a combined pH microelectrode has been developed consisting of an indicator electrode made of IrO(2) prepared using the polymeric precursor method and deposited in a platinum microwire. This electrode was mounted inside a stainless steel needle, the external surface of which was painted with conductive silver ink which is used as reference electrode. This device was compared with a conventional glass electrode, and the results presented linear behavior in the pH range from 2.0 to 12.5, in Na(+) and K(+) solutions, exceeding glass electrodes in the alkaline range. The sensitivity was 56.9 +/- 0.2 mV pH(-1) and using ANOVA test we conclude that the electrode is not sensitive to the presence of alkaline cations such as Li(+), Na(+) or K(+). Finally, the response time (t(95)) was 4.9 to 9.0 s depending on the solution pH. The combined pH microelectrode can be used several times and, after three years, continues to have a response similar to that of a freshly produced one.

• 出版日期2010-12