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

Abstract

CE with C⁴D (CE-C⁴D) 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-C⁴D was also used to estimate the pKa 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-C⁴D 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 24 μmol/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.

Contactless conductivity detection for analytical techniques—Developments from 2012 to 2014

“…Other applications include the determination of three polyphenols in tobacco leafs , a set of 14 lanthanides in simulated spent nuclear reactor fuel , peroxycarboxylates in commercial peracetic acid , and PCR products in genetically modified soybeans . Enzymatic assays of myrosinase were evaluated on the basis of sulphate production and its subsequent CE‐C 4 D determination .…”

Determination of topiramate by capillary electrophoresis with capacitively‐coupled contactless conductivity detection: A powerful tool for therapeutic monitoring in epileptic patients

“…To demonstrate the applicability of the proposed approach, plasma samples from patients under treatment with TPM were analyzed according to the procedure described. It is important to mention that while the combination of CE‐C 4 D has been previously used for the analysis of small molecules including pharmaceutical compounds such as sildenafil/vardenafil , caffeine/paracetamol/ibuprofen , or antibiotics the application to serum samples is rarely reported. Figure shows the results obtained from 10 patients under treatment with TPM.…”

Recent applications and developments of capacitively coupled contactless conductivity detection (CE‐C4D) in capillary electrophoresis

“…A poly(vinyl alcohol) coated capillary in nonaqueous CE mode was adopted. CE with C 4 D was applied for the detection of peroxycarboxylates in aqueous medium (Vidal and Do Lago, ). Oligosaccharide determination was described by Do Lago et al .…”