title: Surface-enhanced Raman spectroscopy of chernozem humic acid and their fractions obtained by coupled size exclusion chromatography-polyacrylamide gel electrophoresis (SEC-PAGE).
abstract: A humic acid extracted from a chernozem soil was fractionated combining size exclusion chromatography and polyacrylamide electrophoresis (SEC-PAGE). Three fractions named A, B, and C+D, with different electrophoretic mobilities and molecular sizes (MS), were obtained and subsequently characterized by thermochemolysis and surface-enhanced Raman spectroscopy (SERS). The data confirmed that fraction A, with the higher MS, was more aliphatic than fractions B and C+D and, in turn, fractions with lower MS (B and C+D) denoted an enrichment in lignin residues. These structural features explain conformational changes when varying the pH in the humic fraction A and indicated that combination of the two techniques is a good approach for characterizing humic substances.
authors.affiliation: Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Cientificas, Serrano 121, 28006 Madrid, Spain. imts158@iem.cfmac.csic.es
authors.forename: S
authors.initials: S
authors.lastname: Sanchez-Cortes
authors.forename: G
authors.initials: G
authors.lastname: Corrado
authors.forename: O E
authors.initials: OE
authors.lastname: Trubetskaya
authors.forename: O A
authors.initials: OA
authors.lastname: Trubetskoj
authors.forename: B
authors.initials: B
authors.lastname: Hermosin
authors.forename: C
authors.initials: C
authors.lastname: Saiz-Jimenez
mesh_terms: D005591:Chemical Fractionation / Q000379:methods*; D002850:Chromatography, Gel / Q000379:methods*; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods*; D006812:Humic Substances / Q000032:analysis*; D012426:Russia; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
chemical_list: D006812:Humic Substances