Extraction of biogenic amines and their dansyl derivatives with reverse microemulsions of bis [2-ethylhexyl] sulphosuccinate (AOT) prior to HPLC determination

L. ROMERO; S. KEUNCHKARIAN; M. RETA

ANALYTICA CHIMICA ACTA

Elsevier

Año: 2006 vol. 565 p. 136 - 144

0003-2670

The ability of reverse microemulsions of the surfactant bis [2-ethylhexyl] sulphosuccinate (AOT) in heptane to extract and preconcentrate eight biogenic amines present in aqueous matrices has been explored. The ?phase transfer? method, in which the surfactant solution is contacted with an aqueous salt solution containing the analytes, has been used as the analytical methodology. The extraction efficiencies have been compared with those obtained by using the ?cloud point? extraction technique with Triton X-114 as surfactant, and with methylene chloride as a typical extracting solvent. In order to improve extraction and detection as compared with the underivatized amines, the fluorescent reagent dansyl chloride has been used to obtain the more hydrophobic and thus, easily extractable dansyl derivatives. Although extraction of most of the biogenic amines is high, extraction of their dansyl derivatives is practically 100%. The procedure was successfully applied to the analysis of commercial fruit juices. The analytical methodology is sensitive, fast, simple and reproducible. The LOD were in the vicinity of 1 and 2 pmol, which is similar or better than other techniques. The micellar phase is compatible with reverse phase HPLC mobile phases, which allow direct injection of the analyte after extraction. This is an advantage over solid phase extraction (SPE), where incomplete recovery can occur. Moreover, AOT showed to be better extracting surfactant for biogenic amines (and their corresponding dansyl derivatives) than Triton X-114 at the same concentration.