Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6610544 | Electrochimica Acta | 2015 | 8 Pages |
Abstract
The ionophore (salph)Co(III)OAc is used here for the first time as a recognition molecule for nitrite in lipophilic membranes. The nature of the recognition process is evaluated by UV-Vis, ATR-IR and potentiometry, while the purity of the compound is confirmed by LC-MS and cyclic voltammetry. Experimental evidence suggests a replacement of the acetate ligand by nitrite. The formation constant between (salph)Co(III)OAc and NO2â, βâ¼108, is estimated potentiometrically with the sandwich membrane method. The analytical parameters, LODâ¼3 μM, linear range of four orders of magnitude, stability over four days, and the selectivity over chloride (log KNO2,ClPOTâ¼-4.1) are similar to previous ionophores for the same ion. Undiluted urine samples were spiked with incremental concentrations of nitrite to characterize the matrix effect. Beyond the observed analytical performance, we aim here to offer a rational study to understand an unconventional charged ionophore recognition process.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Gastón A. Crespo, Majid Ghahraman Afshar, Noelia Barrabés, Marcin Pawlak, Eric Bakker,