INQUISAL   20936
INSTITUTO DE QUIMICA DE SAN LUIS "DR. ROBERTO ANTONIO OLSINA"
Unidad Ejecutora - UE
artículos
Título:
Flow injection system for the on-line preconcentration of Pb by cloud point extraction coupled to USNICP OES
Autor/es:
GIL, R.A. SALONIAA JJAA GÁSQUEZEZ, J.A. OLIVIERII AACC OLSINA
A, R. MARTINEZZ LLDD
Revista:
MICROCHEMICAL JOURNAL
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2010 vol. 95 p. 306 - 310
ISSN:
0026-265X
Resumen:
Abstract A novel method for the determination of Pb by on-line cloud point extraction coupled to inductively coupled plasma optical emission spectrometry with ultrasonic nebulization (USNICP OES) is presented. The cloud point system was formed in the presence of non-ionic micelles of polyethyleneglycolmono-p-nonylphenylether (PONPE 7.5) and was retained in a minicolumn filled with particles of PTFE. Since the micelles of PONPE were able to extract Pb from the solutions, the use of a complexing reagent was not necessary. Afterwards, the surfactant-rich phase containing the analyte was removed from the minicolumn with nitric acid and introduced into the ultrasonic nebulizer. A total enhancement factor of 150 was obtained for a preconcentration time of 3.3 min, with respect to the direct determination of Pb by conventional ICP OES. The values of the detection (3σ) and quantification (10σ) limits for the preconcentration of 10 mL of sample solution were 0.09 µg L− 1 and 0.2 µg L− 1 respectively. The precision, expressed as the relative standard deviation (RSD), for 10 replicate determinations at 5.0 µg L− 1 Pb level was 6.0%. Verification of the accuracy was carried out by analysis of two certified reference materials (NIST SRM 1640e and VKI QC Metal LL1). The method was successfully applied to the determination of Pb in drinking water samples.