title: Microwave-assisted diluted acid digestion for trace elements analysis of edible soybean products.
abstract: A new method for the decomposition of soybean based edible products (soy extract, textured soy protein, transgenic soybeans, and whole soy flour) was developed to essential (Co, Cr, Cu, Fe, Mn, Ni, Se, V, and Zn) and non-essential (As, Ba, Cd, Pb, and Sr) trace elements determination by ICP OES and ICP-MS respectively. Effects related to the concentration of HNO3 (2.1-14.5 mol L(-1)) and the use of hydrogen peroxide on the efficiency of decomposition was evaluated based on the residual carbon content (RCC). It was demonstrated that 2.1 mol L(-1) HNO3 plus 1.0 mL H2O2 was suitable for an efficient digestion, since RCC was lower than 18% and the agreement with certified values and spike recoveries were higher than 90% for all analytes. The concentrations of analytes in the samples (minimum-maximum in mgkg(-1)) were: The concentrations of analytes in the samples (minimum-maximum in mgkg(-1)) were: As (<0.007-0.040), Ba (0.064-10.6), Cd (<0.006-0.028), Co (0.012-102), Cr (0.56-5.88), Cu (6.53-13.9), Fe (24.9-126), Mn (16.4-35.2), Ni (0.74-4.78), Se (<2.90-25), Sr (2.48-20.1), Pb (<0.029-0.11), V (<0.027-20), and Zn (30.1-47.3). Soy-based foods investigated in this study presented variable composition in terms of essential and potentially toxic elements, which can be attributed to different methods of processing.
authors.affiliation: Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador 40170-280, Bahia, Brazil.
authors.forename: José Tiago P
authors.initials: JT
authors.lastname: Barbosa
authors.affiliation: Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Clarissa M M
authors.initials: CM
authors.lastname: Santos
authors.affiliation: Departamento de Ciências Exatas e da Terra, Universidade do Estado da Bahia, Salvador, BA, Brazil.
authors.forename: Vanessa N
authors.initials: VN
authors.lastname: Peralva
authors.affiliation: Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Erico M M
authors.initials: EM
authors.lastname: Flores
authors.affiliation: Departamento de Ciências Exatas e da Terra, Universidade do Estado da Bahia, Salvador, BA, Brazil.
authors.forename: Mauro
authors.initials: M
authors.lastname: Korn
authors.affiliation: Departamento de Química, Universidade Federal de São Carlos, São Carlos, SP, Brazil.
authors.forename: Joaquim A
authors.initials: JA
authors.lastname: Nóbrega
authors.affiliation: Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador 40170-280, Bahia, Brazil. Electronic address: korn@ufba.br.
authors.forename: Maria Graças A
authors.initials: MG
authors.lastname: Korn
mesh_terms: D002244:Carbon / Q000032:analysis; D005504:Food Analysis / Q000379:methods*; D006861:Hydrogen Peroxide; D057230:Limit of Detection; D008872:Microwaves; D017942:Nitric Acid; D012639:Seeds; D045730:Soy Foods / Q000032:analysis*; D013025:Glycine max; D013057:Spectrum Analysis; D014131:Trace Elements / Q000032:analysis*
chemical_list: D014131:Trace Elements; D017942:Nitric Acid; D002244:Carbon; D006861:Hydrogen Peroxide
keywords: ICP OES; ICP-MS; Microwave radiation; Nitric acid; Sample preparation; Soybeans; Trace elements