An improved air-gap electrode and its application to the measurement of carbonate in interstitial water

The air-gap gas sensing electrode according to Růžicka is improved in several aspects. The reliability was increased by the use of a combined glass-reference electrode. A new way of sample introduction gave a better accuracy in practice. The electrode is used to determine carbonate concentrations in the range of 5 · 10−2–5 · 10−4M with an accuracy of 2–9%. The electrode is in use in the analysis of environmental carbonate.