An anionic resin modified by di-2-pyridyl ketone salicyloylhydrazone as a new solid preconcentration phase for copper determination in ethanol fuel samples

• Published in: Journal of the Brazilian Chemical Society Vol. 22; no. 3; pp. 501 - 510
• Main Authors: Garcia, Samara, Gaubeur, Ivanise
• Format: Journal Article
• Language: English; Portuguese
• Published: Sociedade Brasileira de Química 01.03.2011
• Subjects: CHEMISTRY, MULTIDISCIPLINARY; molecular spectrophotometry; ethanol fuel sample; preconcentration; DPKSH; flow analysis
• ISSN: 0103-5053; 1678-4790
• DOI: 10.1590/S0103-50532011000300013

The adsorption of DPKSH onto anionic resin was investigated at 25 ± 1 ºC and pH 12 on the basis of three kinetic models including pseudo-first order, pseudo-second order and intraparticle diffusion. Isotherm equations including Langmuir, Freundlich and Dubinin-Radushkevich (D-R) were successfully applied to model the experimental data. An anionic resin loaded with DPKSH was used in a flow system for the in-line concentration of copper prior to spectrophotometric determination. Under optimized conditions, a linear response was observed between 20 and 80 µg L-1, with limits of detection and quantification estimated at 0.5 and 1.8 µg L-1, respectively, at the 95% confidence level with an enrichment factor of 11. The relative standard deviation was estimated to be 2.6% for 32 µg L-1 Cu(II) (n = 20). The results obtained for copper determination in ethanol fuel samples agreed with those achieved by flame atomic absorption spectrometry (F AAS) at the 99% confidence level.