ABSTRACT: A method is presented for matrix separation, preconcentration and determination by hydride generation atomic fluorescence
spectrometry of trace amounts of Se(IV). It is based on solidified floating drops of 1-undecanol that are capable of extracting
the target analyte after chelation with a water soluble ligand and subsequent ultrasound-assisted back-extraction into a aqueous
solution. Hydride generation was then accomplished by reaction with a solution of sodium borohydride. Under optimized conditions,
an enrichment factor of 15 and a linear calibration plot in the range from 0.01 to 5.0μg L−1 were achieved using a 10.0mL sample. The detection limit (3σ) is 7.0ng L−1, and the relative standard deviation (RSD) is 2.1% at 1.0μg L−1 (n = 11). The method was applied to determination of Se(IV) in different real water samples through recovery experiments and
subsequently validated against two certified reference materials.
A solidified floating organic drop microextraction coupled with hydride generation atomic fluorescence spectrometry for the
determination of Se(IV) is described.
KeywordsSolidified floating organic drop microextraction–Ultrasound-assisted back-extraction–Hydride generation atomic fluorescence spectrometry–Se(IV)
Microchimica Acta 04/2012; 173(1):267-273. · 3.03 Impact Factor
ABSTRACT: A new approach to performing extraction and preconcentration employing functionalized magnetic nanoparticles for the determination of trace metals is presented. Alumina-coated iron oxide nanoparticles were synthesized and used as the solid support. The nanoparticles were functionalized with sodium dodecyl sulfate and used as adsorbents for solid phase extraction of the analyte. Extraction, elution, and detection procedures were performed sequentially in the sequential injection lab-on-valve (SI-LOV) system followed by electrothermal atomic absorption spectrometry (ETAAS). Mixtures of hydrophobic analytes were successfully extracted from solution using the synthesized magnetic adsorbents. The potential use of the established scheme was demonstrated by taking cobalt as a model analyte. Under the optimal conditions, the calibration curve showed an excellent linearity in the concentration range of 0.01-5 μg L(-1), and the relative standard deviation was 2.8% at the 0.5 μg L(-1) level (n=11). The limit of detection was 6 ng L(-1) with a sampling frequency of 18 h(-1). The present method has been successfully applied to cobalt determination in water samples and two certified reference materials.
Analytica chimica acta 02/2012; 713:92-6. · 4.31 Impact Factor
ABSTRACT: In this work, a kojic acid electrochemical sensor, based on a non-covalent molecularly imprinted polymer (MIP) modified electrode, had been fabricated in the lab-on-valve system. The sensitive layer was synthesized by cyclic voltammetry using o-phenylenediamine as the functional monomer and kojic acid as the template. The template molecules were then removed from the modified electrode surface by washing with NaOH solution. Differential pulse voltammetry method using ferricyanide as probe was applied as the analytical technique, after extraction of kojic acid on the electrode. Chemical and flow parameters associated with the extraction process were investigated. The response recorded with the imprinted sensor exhibited a response in a range of 0.01-0.2 μmol L(-1) with a detection limit of 3 nmol L(-1). The interference studies showed that the MIP modified electrode had excellent selectivity. Furthermore, the proposed MIP electrode exhibited good sensitivity and low sample/reagent consumption, and the sensor could be applied to the determination kojic acid in cosmetics samples.
Talanta 10/2011; 85(5):2522-7. · 3.79 Impact Factor