Capillary electrophoresis with capacitively coupled contactless conductivity detection applied to the quantitation and to the determination of physical-chemical properties of peroxycarboxylates in aqueous medium

Author(s)

Vidal, Denis T. R. ; do Lago, Claudimir L.

• Document type: Journal article
• Source: ELECTROPHORESIS; v. 34, n. 14, p. 7-pg., 2013-07-01.

Abstract

CE with (CD)-D-4 (CE-(CD)-D-4) was successfully applied to the investigation of performate, peracetate, and perpropionate in aqueous medium. Ionic mobilities, diffusion coefficients, and hydrodynamic radii were obtained for the first time for these species. CE-(CD)-D-4 was also used to estimate the pK(a) values of the peroxycarboxylic acids. Because the peroxycarboxylates (POCs) undergoes hydrolysis while migrating, a simple calibration curve cannot be used for quantitation. Thus, an indirect calibration approach was used. The new method was used to monitor the formation of peroxycarboxylic acids from hydrogen peroxide and the carboxylic acid as well as to the quantitation of peracetic acid in a commercial sample. The CE-(CD)-D-4 method compares favorably with the conventional titration method because of the possibility of speciation of the POC, the low sample consumption, and the low LOD (14, 8, and 24mol/L for performate, peracetate, and perpropionate, respectively). Although POCs are structural isomers of monoalkyl carbonates, they have greater hydrodynamic radii, which suggests that the positions of the oxygen atoms in the molecules have a direct impact in the charge density and consequently on the hydration atmosphere. (AU)

• FAPESP's process: 12/06642-1 - Formation and properties of adducts of organic hydroxy-compounds with carbonate in aqueous medium and biological conditions
• Grantee: Claudimir Lucio Do Lago
• Support Opportunities: Regular Research Grants
• FAPESP's process: 11/02156-2 - The use of capillary electrophoresis with contactless conductivity detection for obtaining analytical and physicochemical parameters of peroxycarbonate, peroxyacids, and monoethyl pyrocarbonate.
• Grantee: Denis Tadeu Rajh Vidal
• Support Opportunities: Scholarships in Brazil - Post-Doctoral