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Determination of organic acids in wine by zone electrophoresis on a chip with conductivity detection
Author(s) -
Masár Marián,
Poliaková Katarína,
Danková Mariana,
Kaniansky Dušan,
Stanislawski Bernd
Publication year - 2005
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200500061
Subject(s) - wine , chemistry , chromatography , ionic strength , electrolyte , calibration curve , sample preparation , electrophoresis , capillary electrophoresis , context (archaeology) , conductivity , malic acid , standard solution , analytical chemistry (journal) , detection limit , organic chemistry , aqueous solution , paleontology , food science , electrode , citric acid , biology
An appropriate combination of separation mechanisms (simultaneous use of differences in p K values, host‐guest complexations, and the ionic strength dependences of the actual ionic mobilities) provided zone electrophoresis (ZE) resolution of 22 organic and inorganic acids expected in wines on a polymethylmethacrylate (PMMA) chip with integrated conductivity detection. These separating conditions offered a framework for the ZE determination of organic acids responsible for some important organoleptic characteristics of wines (tartrate, malate, succinate, acetate, citrate, and lactate). The ZE procedure developed in this context is simple and rapid (ca. 10 minutes’ analysis time), while affording reproducible migration and quantitation data for the acids. For example, 0.8–2.0% RSD values characterized the migration times of the acids for 25 repeated ZE runs with the same sample carried out in 5 days in the background electrolyte solution prepared freshly on a daily basis, while 3–5% RSD values were typical for the accompanying peak area data. The concentration ranges within which the acids of analytical interest could be determined in one ZE run covered all wine samples included in our study (100–400‐fold sample dilutions were needed to work under the conditions corresponding to the validities of the calibration data). 90–110% recoveries of the acids as obtained repeatedly for one of the reference wine samples used in our experiments indicate a good predisposition of the present method to provide accurate analytical results. This statement also supports the results from the determination of the acids in reference wine samples with claimed concentrations of malic (five samples), tartaric (one sample), and lactic (one sample) acids.