A nitrate-selective electrode based on tris(2,2 ',2 ''-salicylideneimino)triethylamine

A new nitrate-selective liquid-membrane electrode based on the tris(2,2',2 " -salicylideneimino)triethylamine-iron(III) complex has been developed. Th is electrode exhibits a linear Nernstian response over the range 10(-1) - 1 0(-4) M of nitrate, with a slope of 54.3 +/- 0.9 mV per p[NO3]. The effects of the pH and the liquid-membrane composition were also investigated. ne l ifetime of the electrode is at least one month. The selectivity coefficient s for ten monovalent ions were calculated. The preparation procedure of the electrode is very easy and inexpensive. Moreover, the proposed electrode w as applied for the determination of nitrate in fertilizers.