CARLOS ALBERTO DA SILVA QUEIROZ

CARLOS ALBERTO DA SILVA QUEIROZ

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Production of high purity samarium acetate for use in nuclear area
2021 - QUEIROZ, CARLOS A. da S.; PEDREIRA FILHO, WALTER dos R.
Samarium is currently used in many applications, such as catalysts, lasers and metal alloys. Samarium is also employed to absorb neutrons in nuclear reactors. In medicine, samarium is used in the form of radioactive 153Sm to produce radiopharmaceuticals. A simple process for the preparation of pure samarium acetate was studied. The raw material, which was used in the form of rare earth carbonates was produced industrially from the chemical treatment of Brazilian monazite. Ion exchange chromatography was performed using a strong cationic resin to fractionate rare earth elements (REE). Under these conditions, 99.9% pure Sm2O3 and yield greater than or equal 60% was eluted by ammonium salt of ethylenediaminetetraacetic acid (EDTA) solution in con-trolled pH. The EDTA-samarium complex was transformed into samarium oxide, which was subsequently dis-solved in acetic acid to obtain the samarium acetate. Molecular absorption spectrophotometry was used to moni-tor the samarium and sector field inductively coupled plasma mass spectrometry was used to certify the purity of the samarium acetate. The solid salt was characterized by chemical analysis, thermal analysis, infrared spectros-copy and X ray diffraction. The analytical data collected allowed to conclude that stoichiometric formula for the samarium acetate obtained is Sm(CH3COO)3.4.H2O.
Preparacao de nitrato de cerio de alta pureza
1995 - AVILA, D.M.; QUEIROZ, C.A.S.; MUCCILLO, E.N.S.
Sintese e caracterizacao de Lnsub(2)Osub(3) (Ln=Ce e Gd) de alta pureza
1999 - AVILA, D.M.; MUCCILLO, E.N.S.; QUEIROZ, C.A.S.
Obtencao de padrao de Lasub(2)Osub(3)
1991 - QUEIROZ, C.A.S.; ABRAO, A.
Sintese e caracterizacao de Ysub(1)Basub(2)Cusub(3)Osub(7-x) utilizando-se materias primas nacionais
1991 - ESCANHOELA, C.M.F.; LEME, D.G.; QUEIROZ, C.A.S.; MORATO, S.P.
Obtaining pure praseodymium acetate to use in researches and development
2010 - QUEIROZ, CARLOS A. da S.; ROCHA, SORAYA M.R. da; PEDREIRA, WALTER R.; SENEDA, JOSE A.; LOBO, RAQUEL M.; S. FILHO, WALTER
This paper presents a simple and economical procedure to obtain high purity praseodymium acetate. The raw material in the form of mixed rare earths carbonate comes from a industrial separation of rare earths, thorium and uranium in the brasilian monazite. It is used the tecnique of strong cation exchange resin, proper to water treatment, to the praseodymium's fractionation and it is achieved a purity of 99.9% in Pr6O11 and yield greater than or equal 60%, with the elution of rare earths by EDTA solution in pH controlled. The complex of EDTA-praseodymium is transformed in praseodymium oxide, subsequently the oxide is dissolved in acetic acid to obtain the praseodymium acetate. The molecular absorption spectrophotometry tecnique is used to monitoring the praseodymium content during the process and mass spectrometry to certification the purity of the praseodymium acetate. The typical praseodymium acetate obtained presents the followings contaminants in micrograms per gram: Sc(18.20±0.22); Y (20.20 ± 0.20); La (6.75 ± 0.81); Ce (26.10 ± 0.70); Nd (3.31 ± 0.63); Sm (18.30 ± 0.80); Eu (17.00 ± 0.90); Gd (19.40 ± 0.40); Tb (16.30 ± 0.50); Dy (16.90 ± 0.50), Ho(17.90 ± 0.10); Er (18.40 ± 0.70); Tm (16.90 ± 0.10); Yb (17.60 ± 0.60); Lu (17.70 ± 0.50). The high purity praseodymium acetate comes being applied, replacing the imported product, in research and development area on rare earth catalysts.
Advanced mass spectrometric applied to determinated of composition in lead (Pb-208) from residues of thorium facilities
2007 - SENEDA, JOSE A.; QUEIROZ, CARLOS A. da S.; RIZZO, SORAYA M. da R.; DIAS, MAURO S.; KAKAZU, MAURICIO H.; ABRAO, ALCIDIO
Determinacao de impurezas de terras raras em oxido de neodimio de alta pureza (Ndsub(2)Osub(3)) pela espectrometria de massa com fonte de plasma induzido por argonio (HR-ICPMS) com separacao de matriz pelo cromatografo de liquido de alta eficiencia (HPLC)
1999 - PEDREIRA FILHO, W.R.; SARKIS, J.E.S.; BONA, I.A.T.; QUEIROZ, C.A.S.; ABRAO, A.; RODRIGUES, C.
Caracterizacao termoanalitica de peroxido de samario
1994 - QUEIROZ, C.A.S.; MATOS, J.R.; ABRAO, A.
Separacao de cerio e fracionamento de terras raras a partir dos cloretos mistos
1981 - QUEIROZ, C.A.S.; SOOD, S.P.; ABRAO, A.