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Determination of ultra-trace cobalt ion by ET-AAS after preconcentration by pyridine-functionalized magnetic nanoparticles

Y.Ghorbani, A.Rahimi

We present a study on the application of magnetic nanoparticles (MNPs) prepared fromFe3O4 and functionalizedwith pyridine as anadsorbent for the solid-phase extraction of trace quantities ofCo(II) ion. The pyridine groupwas immobilized on the surface of theMNPsbycovalent bondingof isonicotinamide.The modifiedMNPs can be readilyseparated froman aqueous solution byapplyingan externalmagnetic field.Effects of pH, the amount of functionalizedMNPs, type and quantity of eluent, desorption time on the extraction efficiencywere optimized.The amount ofCo (II) Original Article ChemXpress 5(3), 098-102, (2014) ISSN(Print) : 2320 –1967 ISSN(Online) : 2320 –1975 INTRODUCTION Cobalt is a natural element found throughout the environment and used tomake super alloys (alloys that maintain their strength at high temperatures approaching theirmeltingpoints) and inpigmentmanufacture. It can benefit or harmhuman health. In general, heavy metal ions are toxic, non-biodegradable, and tend to be accumulated in vital human organs,where theycan actprogressivelyover a longperiodthroughfoodchains. The determination of trace heavymetal ions in environmental samples has receivedincreasingattention.Some trace elements are essential to man, whose daily requirement isonlyafewmilligrams.However, if ingested inhighlevels, this canbeharmful tohumanhealth.Thus, the elemental composition is essential to ensure food quality[1]. Cobalt is an essential trace element that has an important role inmanybodilyfunctions. It is toxic in was then determined usingElectrothermalAtomicAbsorption Spectroscopy(ETAAS).Under the optimized conditions, the detectionlimit and preconcentration factor are 0.11 ìg L-1 and 200, respectively, and the relative standard deviation (at 10 ìgL-1; for n=5) is 3.5%. Themethod had a linear analytical range from0.10 to 80 ìg L-1 andwas applied to determineCo (II) inwater samples.