Estudio preliminar en la miniaturización de electrodos selectivos a iones Pb(II) basados en derivados de tiourea.

The present work reports the miniaturization of a solid-contact lead (II) ion selective electrode based on 1-benzoyl-3,3-diethylthiourea (BDE) as neutral carrier and tris-2-ethylhexilphosphate (TEHP) as mediator solvent in a polivynil chloride (PVC) matrix. Microelectrodes were prepared with glass capillaries of different diameters (2, 1 y 0,8 mm) and illustrates a good sensitivity to the metallic cation, with a slope close to a Nernstian logarithmic relationship for a divalent ion (29,53 mV/decade). Furthermore, the microelectrodes shows detection limits in order of 10-6 mol/L and a linearity range from 10-6 to 10-3 mol/L. These results are similar to reports for others sensors based on thiourea derivatives and even for commercial selective electrodes. [ABSTRACT FROM AUTHOR]