DEVELOPMENT OF A SECOND TYPE ELECTRODE BASED ON THE SILVER/SILVER IBUPROFENATE PAIR FOR IBUPROFEN QUANTIFICATION IN PHARMACEUTICAL SAMPLES

Ibuprofen is a widely used pharmaceutical because of its therapeutic properties; it is considered a safe medicament, thus it does notrequire medical prescription to be sold. However, in order to ensure consumer?s health it is indispensable that the pharmaceuticalindustry relies on analytic methods for its quantification. Potentiometry has proven to be a successful technique using second typeelectrodes, which in agreement with Nernst?s equation can detect anions activity. On consideration of this, this research work presentsthe development of a second type electrode based on the silver/silver ibuprofenate pair. This involved modifying a pure silver wireusing a sodium ibuprofenate solution, to obtain the redox pair. The following analytic parameters were obtained with the aid of themodified electrode: a sensitivity of -0.049 V decade [ibuprofenate]?1, 8 mol L-1 for the detection limit and a quantification limit of1.2 mol L-1. The repeatability value in terms of the relative standard deviation was 5.9%. After performing an interferences analysisusing some ions and excipients, it was corroborated that there were none, thus allowing appropriate quantification on a real sample.