DEVELOPMENT OF A NITRATE ION-SELECTIVE EL ECTRODE

A liquid membrane that works as an ion selective electrode (ISE) has b een obtained from tetradecylammonium nitrate (a quaternary ammonium sa lt). This salt is nitrate ion selective because its structural charact eristics allow this molecular recognition. The membrane was obtained u sing a PVC matrix. DBP as an intermediate solvent, and cyclohexanone i n order to have a good homogenization, as well as, a complete dissolut ion of components. The ISE obtained has a Nernstiana answer -57,8 +/- 3 mv/dec. Interferences were evaluated taking into account the potenti ometric measurement of selectivity coefficient according to the modifi cation of Nernst equation in the separate solution method.