Factors affecting the analytical applications of zeolite modified electrodes: indirect detection of nonelectroactive cations

摘要: Abstract Carbon paste electrodes modified with several types of copper-doped zeolites were evaluated as sensors for nonelectroactive cations in a flow injection system. After having described the amperometric detection mechanism and proposed an efficient procedure to achieve good reproducibility successive measurements, it was shown how various experimental parameters influenced quantitative determination potassium ions (chosen reference cationic species), such applied potential, mobile phase composition rate, ionic strength sample solution, or volume. The analysis then extended other mono- divalent selectivity series established relation wherever A, X, Y, clinoptilolite used. It concluded that sensor's response mainly governed by diffusion both electron transfer co-factor (Cu 2+ species) analytes, rather than thermodynamic predictions related ion exchange equilibrium despite fact allowed occur only after Cu species analyte. Detection limits around 10 −6  M obtained alkali metal, ammonium, calcium magnesium using zeolite Y electrode 0.01 M tetrabutylammonium bromide phase.