Optimization of the synthesis of magnetic nanoparticles by solid sampling high resolution continuum source graphite furnace atomic absorption spectrometry and multi-response surface methodology

Vereda-Alonso, Elisa Isabel; López-Guerrero, María del Mar; García-de-Torres, Amparo; Cano-Pavón, José Manuel; Siles-Cordero, María Teresa

Optimization of the synthesis of magnetic nanoparticles by solid sampling high resolution continuum source graphite furnace atomic absorption spectrometry and multi-response surface methodology

Vereda-Alonso, Elisa Isabel,López-Guerrero, María del Mar,García-de-Torres, Amparo,Cano-Pavón, José Manuel,Siles-Cordero, María Teresa

Published: 2016-10-04
Repository: riuma.uma.es
Language: en

Abstract

Magnetic nanoparticles (MNPs) are a new kind of nanometer-sized materials superparamagnetic with potential applications as magnetic carries for various biomedical uses, wastewater remediation, preconcentration of various anions and cations, etc.1 The excellent properties of MNPs are strongly influenced by the size of the nanoparticles. Another important factor is the amount of iron present. In this work a simple, rapid and inexpensive approach was developed for direct determination of Fe concentration and particle size of solid MNPs by solid sampling high resolution continuum source graphite furnace atomic absorption spectrometry (SS-HR-CS-GFAAS). A new strategy in evaluating area and slope of the obtained absorbance signals for a line of Fe (352.614 nm) with low sensitivity was developed for both determinations. For this purpose, five furnace program parameters, atomization heating rate, atomization temperature, pyrolysis heating rate, pyrolysis temperature and hold pyrolysis time, were optimized with the employ of two multiple response surface designs. The response variables chosen were: atomization signal area/weighted mass of MNPs and the inverse of the upslope of the atomization signal/weighted mass of MNPs. With the optimized furnace parameters, good calibration curves (R > 0.997) were obtained with liquid iron standards (for Fe determination) and with MNPs samples with certified size particle (for size particle determination). The determination of the MNPs size was validated by transmission electron microscopy (TEM). The developed method was used in the optimization of the synthesis of MNPs by a multi-response surface methodology. The MNPs were synthesized by a modified chemical co-precipitation method, where three factors (reaction time, volume and concentration of NH3) were investigated using two responses variables (Fe concentration and 1/size of MNPs). From this study was concluded that the highest Fe concentrations were obtained with low volumes of NH3, and the smallest sizes of MNPs were obtained with high NH3 concentrations. Therefore, the optima esperimental conditions obtained were: reaction time: 55 min; NH3 volume: 10 mL; and NH3 concentration 30%. The synthesis of MNPs with the optimized parameters result in MNPs with around 65% in Fe and a size of 17 nm. Optimum size ranges from 13 to 18 nm are preferable for their use as absorbent in solid phase extraction because of their higher magnetic moment per particle.2 [1] M.H. Mashhadizadeh, Z. Karami, J. Hazard Mater., 2011, 190, 1023. [2] M. Marciello, V. Connord, S. Veintemillas-Verdaguer, M.A. Vergés, J. Carrey, M. Respaud, C.J. Serna, M. P. Morales, J. Mater. Chem. B, 2013, 1, 5995.

Full text

Op imiza ion o he syn hesis o Magne ic Nanopa icles by Solid Sampling High Resolu ion Con inuum Sou ce G aphi e Fu nace A omic Abso p ion Spec ome y and Mul i-Response Su ace Me hodology Elisa Isabel Ve eda Alonso (1), M. Ma López Gue e o (1), Ampa o Ga cía de To es (1), José Manuel Cano Pa ón (1), M. Te esa Siles Co de o (1) (1) Uni e si y o Málaga Campus de Tea inos Málaga Spain Email: ei e [email protected] P esen ing au ho : M. Ma López Gue e o Type: O al Theme: E. Ma e ials, De ices and Nanochemis y Topic: E3. Analy ical Techniques, Cha ac e isa ion and P ope ies Keywo ds: Magne ic nanopa icles, Solid sampling HR-CS-ETAAS, Mul i- esponse su ace me hodology SUMMARY: Magne ic nanopa icles (MNPs) a e a new kind o nanome e -sized ma e ials supe pa amagne ic wi h po en ial applica ions as magne ic ca ies o a ious biomedical uses, was ewa e emedia ion, p econcen a ion o a ious anions and ca ions, e c.1 The excellen p ope ies o MNPs a e s ongly in luenced by he size o he nanopa icles. Ano he impo an ac o is he amoun o i on p esen . In his wo k a simple, apid and inexpensi e app oach was de eloped o di ec de e mina ion o Fe concen a ion and pa icle size o solid MNPs by solid sampling high esolu ion con inuum sou ce g aphi e u nace a omic abso p ion spec ome y (SS-HR-CS-GFAAS). A new s a egy in e alua ing a ea and slope o he ob ained abso bance signals o a line o Fe (352.614 nm) wi h low sensi i i y was de eloped o bo h de e mina ions. Fo his pu pose, i e u nace p og am pa ame e s, a omiza ion hea ing a e, a omiza ion empe a u e, py olysis hea ing a e, py olysis empe a u e and hold py olysis ime, we e op imized wi h he employ o wo mul iple esponse su ace designs. The esponse a iables chosen we e: a omiza ion signal a ea/weigh ed mass o MNPs and he in e se o he upslope o he a omiza ion signal/weigh ed mass o MNPs. Wi h he op imized u nace pa ame e s, good calib a ion cu es (R > 0.997) we e ob ained wi h liquid i on s anda ds ( o Fe de e mina ion) and wi h MNPs samples wi h ce i ied size pa icle ( o size pa icle de e mina ion). The de e mina ion o he MNPs size was alida ed by ansmission elec on mic oscopy (TEM). The de eloped me hod was used in he op imiza ion o he syn hesis o MNPs by a mul i- esponse su ace me hodology. The MNPs we e syn hesized by a modi ied chemical co-p ecipi a ion me hod, whe e h ee ac o s ( eac ion ime, olume and concen a ion o NH3) we e in es iga ed using wo esponses a iables (Fe concen a ion and 1/size o MNPs). F om his s udy was concluded ha he highes Fe concen a ions we e ob ained wi h low olumes o NH3, and he smalles sizes o MNPs we e ob ained wi h high NH3 concen a ions. The e o e, he op ima espe imen al condi ions ob ained we e: eac ion ime: 55 min; NH3 olume: 10 mL; and NH3 concen a ion 30%. The syn hesis o MNPs wi h he op imized pa ame e s esul in MNPs wi h a ound 65% in Fe and a size o 17 nm. Op imum size anges om 13 o 18 nm a e p e e able o hei use as abso ben in solid phase ex ac ion because o hei highe magne ic momen pe pa icle.2 [1] M.H. Mashhadizadeh, Z. Ka ami, J. Haza d Ma e ., 2011, 190, 1023. [2] M. Ma ciello, V. Conno d, S. Vein emillas-Ve dague , M.A. Ve gés, J. Ca ey, M. Respaud, C.J. Se na, M. P. Mo ales, J. Ma e . Chem. B, 2013, 1, 5995.