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Abstract
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In this study, a clean and simple magnetic solid-phase extraction (MSPE) procedure using magnetite/graphene oxide nanocomposite
as an adsorbent was developed for melamine separation and preconcentration from water and dairy products. After
synthesis and characterization of the adsorbent, adsorption isotherms and kinetic studies of the adsorption were carried out.
The analyte quantification was performed by reversed phase high-performance liquid chromatography after elution of the
preconcentrated analytes from the adsorbent surface. Several factors affecting the extraction/preconcentration procedure such
as pH, adsorbent amount, extraction time, sample volume, type, and volume of eluent were investigated. The optimizing of some
important parameters was assessed by employing a response surface method. The constructed calibration curve in the optimized
conditions is linear in the working range of 0.10–100 μg L−1 with a correlation coefficient of 0.9999. The detection limit, limit of
quantification, and enrichment factor are 0.03 μg L−1, 0.10 μg L−1, and 500, respectively. The melamine relative recoveries from
different real samples are between 97.20 and 103.10% with relative standard deviations of 1.07–4.98%.
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