Potentiometric sensor for hydrogen ion based on N,N'-dialkylbenzylethylenediamine neutral carrier in a poly(vinyl chloride) membrane with polyaniline solid contact.

Hydrogen ion selective solid contact electrodes based on N,N'-dialkylbenzylethylenediamine (alkyl=butyl, hexyl, octy, decyl) are prepared. Solid contact electrodes and coated wire electrodes have been fabricated from polymer cocktail solutions based on N,N'-dialkylbenzylethylenediamine (alkyl=butyl, hexyl, octy, decyl). We showed that the response range and slopes are influenced by the alkyl chain length. Response ranges and Nernstian slops for solid contact electrodes were slightly better than for coated wire electrodes. Solid contact electrodes were shown linear selective to hydrogen ion in the pH ranges pH 4.5-13.0, 4.2-13.1, 3.4-13.0 and 3.0-13.2. and their Nernstian slopes were 49.7, 50.8, 51.5 and 53.7 mV pH(-1) at 20+/-0.2 degrees C, respectively. Stability is also improved especially when compared with coated wire electrodes. The 90% response time was <2 s and their electrical resistance varied in the range 2.37-2.76 MOmega. Especially solid contact electrodes with N,N'-didecylbenzylethylenediamine have shown the best selectivity and reproducibility of e.m.f..