Determination of neutral diols and carboxylic acids formed during glycerol electrooxidation by capillary electrophoresis with dual (CD)-D-4

Autor(es)

Reis Teixeira, Wanderson Sirley ^[1] ; Ferreira Santos, Mauro Sergio ^[1] ; Gruber, Jonas ^[1] ; Rolf Gutz, Ivano Gebhardt ^[1] ; Lopes, Fernando Silva ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, Av Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Talanta; v. 178, p. 1040-1045, FEB 1 2018.
• Citações Web of Science: 5

Resumo

Methods for determination of glycerol and its electrooxidation products (neutral diols and carboxylates) by capillary electrophoresis (CE) with dual capacitively coupled contacdess conductivity detectors (C4D) are presented. Glycerol, dihydroxyacetone and glyceraldehyde were detected as anionic borate complexes in less than 3 min under counter Electroosmotic Flow (EOF) mode (resolution of the critical pair of 1.8). Limits of detection (LODs) of 15, 15 and 10 mu mol L-1 were obtained for glycerol, dihydroxyacetone and glyceraldehyde, respectively. Two methods of separation were used for the separation of carboxylates. The first one used the same Back Ground Electrolyte (BGE) containing borate, and the second used a BGE (pH 6.1) composed by 2-(N-morpholino) ethanesulfonic acid (IVIES), L-Histidine and a flow modifier. Better separation and LODs for carboxylates were obtained using Mes/Histidine as BGE. However, along with the non -applicability of this BGE to the determination of neutral diols, observation of the (CD)-D-4 signals at two different points of the capillary (10 and 50 cm apart from the injection tip) revealed interaction of the flow modifier with some species (mesoxalate and glyoxylate). The electrooxidation of a glycerol sample in alkaline media on an 8 cm(2) gold working electrode was evaluated by the developed methods. After 16 h of electrolysis, 87% of the glycerol had been oxidized and formate, glycolate, hydroxypyruvate and glycerate were detected as the main products. (AU)

• Processo FAPESP: 12/06642-1 - Formação e propriedades de adutos de hidróxi-compostos orgânicos com carbonato em meio aquoso e condições biológicas
• Beneficiário: Claudimir Lucio Do Lago
• Modalidade de apoio: Auxílio à Pesquisa - Regular