Determination of biogenic amines in wines by ion-pair liquid chromatography and post-column derivatization with 1,2-naphthoquinone-4-sulphonate.

A liquid chromatographic method with post-column derivatization for the determination of biogenic amines in wines is proposed. The method is based on the separation of amines by ion-pair chromatography using sodium heptanesulfonate (SHS) and on-line labeling of analytes with 1,2-naphthoquinone-4-sulfonate. The principal factors influencing the separation (acetonitrile and SHS concentration) have been considered for the optimization of the elution gradient through factorial design and multicriteria decision-making. Figures of merit have been established using red wine samples. Detection limits range from 0.2 to 3 mg L(-1), the peak area run-to-run repeatability from 1.6 to 4.6% and the retention time repeatability lower than 1.2%. Recoveries ranging from 92 and 108% prove the accuracy of the method for determining ethanolamine, ethylamine, histamine and tyramine in commercial red wines. The proposed method has been applied to the analysis of wines from different Spanish regions.

Flow-injection determination of amine contaminants in cyclamate samples based on temperature for controlling selectivity.

This paper describes a flow-injection (FI) method for the simultaneous determination of aniline and cyclohexylamine impurities in cyclamate products. The method consists of the derivatization of amines with 1,2-naphthoquinone-4-sulfonate under selective and non-selective conditions. Here, the selectivity is achieved by working at 20 degree C, at which only aniline reacts, whilst higher temperatures (80 degree C) lead to a non-selective reaction of the two analytes. The FI manifold is composed of two flow cells for the spectrophotometric detection of derivatives at 480 nm. Experimental conditions have been optimized by factorial design and multicriteria making approach. Quantification is accomplished by differential analysis of the analyte contributions in the double peaks generated when the sample reaches cell 1 and cell 2. Results obtained with the proposed method are in satisfactory agreement with those provided by the standard method for the analysis of cyclamate samples.