INVESTIGADORES
PACHECO Pablo Hugo
artículos
Título:
On-line preconcentration and speciation analysis of inorganic vanadium
Autor/es:
PABLO H. PACHECO, ROBERTO A. OLSINA , PATRICIA SMICHOWSKI, LUIS D. MARTINEZ
Revista:
TALANTA
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2007 p. 593 - 598
ISSN:
0039-9140
Resumen:
A study was undertaken to ascertain the analytical capabilities of combined ICPOES with ultrasonic nebulization to perform on-line preconcentration and speciation of inorganic V species in urine samples using a micro-column packed with l-methionine immobilized on controlled pore glass (CPG) as solid phase extractant. At pH 5.0, l-methionine is selective only towards V(V) while, total vanadium was quantitatively adsorbedby the solid phase at pH 9.0 [as V(V)] due to V(IV) oxidation in alkali media. Vanadium species retained by l-methionine were quantitatively eluted from the column with 10% HCl. Effects of acidity, sample flow rate, concentration of eluent and interfering ions on the recovery of the analytes have been systematically investigated. The detection limit (3ó) of V is 0.008 ngmL−1 for USNICPOES with an enhancement factor of 900 (10 for USN and 90 for l-methionine), and the relative standard deviation (R.S.D.) is better than 2%. The proposed method has been applied to the determination of inorganic V(V) and V(IV) in urine.l-methionine immobilized on controlled pore glass (CPG) as solid phase extractant. At pH 5.0, l-methionine is selective only towards V(V) while, total vanadium was quantitatively adsorbedby the solid phase at pH 9.0 [as V(V)] due to V(IV) oxidation in alkali media. Vanadium species retained by l-methionine were quantitatively eluted from the column with 10% HCl. Effects of acidity, sample flow rate, concentration of eluent and interfering ions on the recovery of the analytes have been systematically investigated. The detection limit (3ó) of V is 0.008 ngmL−1 for USNICPOES with an enhancement factor of 900 (10 for USN and 90 for l-methionine), and the relative standard deviation (R.S.D.) is better than 2%. The proposed method has been applied to the determination of inorganic V(V) and V(IV) in urine.
