Determinação potenciométrica de íons cloreto utilizando análise por injeção em fluxo com materiais de baixo custo

Abstract

This work describes the application of a flow injection analysis system (FIA) composed of alternative and low cost materials, using potentiometry as electroanalytical technique. It is also investigated the feasibility of its insertion as didactic experiment in the discipline of Instrumental Analysis I of the course of Graduation in Chemistry of the FACIP-UFU. The methodology and technique used are part of the syllabus of the discipline, however the cost for the traditional application of it is high, making it impossible to study it in practical activities. Thus, there was a need to adapt the method to make it feasible to apply it as a didactic tool. The advantage of the method involving electroanalytical techniques is that it fits into the concepts adopted by green chemistry, since, due to the high sensitivity, it is possible to work in low concentrations, which implies a lower consumption of reagents and, consequently, lower Generation of waste. Due to the ease of adaptation in the systems configuration, the FIA methodology proves to be effective for the system under study, becoming even more relevant to the innovation proposed by this work when combined with the possibility of replacing the peristaltic pump with a hospital enteral nutrition bottle with capacity for 300 mL, because it uses only the force of gravity to make it a good fluid propellant. After controlling for all parameters, such as flow and sampling loop, the method proved to be efficient in determining the concentration of chloride ions to the prepared standards, in commercial samples new tests should be done to validate the method.