RP-HPLC study of redox equilibria in vanadium-PAR binary and ternary systems: Direct determination of vanadium in steel
Sławomir Oszwałdowski , Maciej Jarosz
AbstractThe reversed-phase high-performance liquid Chromatographic (RP-HPLC) behaviour of the binary chelates of V(V) and V(IV) with 4-(2-pyridylazo) resorcinol (PAR) and ternary chelates of vanadium with PAR and auxiliary ligands: hydrogen peroxide, hydroxylamine, tartrate and citrate were studied using a C18 column. The complex double-peak chromatograms of V(IV)/V(V)-PAR systems were studied and the origin of each peak was proved. Vanadium in ternary systems with PAR and hydrogen peroxide was found exclusively in V(V)-H2O2-PAR complex (single peak on the chromatogram) despite its initial oxidation state. The double role of hydroxylamine (complex agent and reductor) in vanadium systems with PAR was confirmed: in the V(V) system three species were identified (V(V)-PAR, V(V)-NH2OH-PAR and V(IV)-PAR), but in the V(IV) system only two: V(IV)-PAR and V(V)-NH2OH-PAR. Citrate and tartrate giving single peak were found as auxiliary ligands in ternary V(V) systems of analytical importance. Due to its masking potential towards iron (III) ions, citrate was chosen as the most suitable third component of a ternary vanadium system with PAR, to form the basis of an RP-HPLC method for direct determination of V in steel.
|Journal series||Microchimica Acta, ISSN 0026-3672, 1436-5073|
|Keywords in English||Analytical Chemistry, Characterization and Evaluation Materials, high-performance liquid chromatography, Inorganic Chemistry, Monitoring/Environmental Analysis/Environmental Ecotoxicology, Physical Chemistry, redox equlibria, steel analysis, vanadium speciation, V(IV)/V(V)-PAR binary and ternary systems|
|Publication indicators||= 12; = 12.0|
|Citation count*||12 (2016-05-30)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.