Rapid automated high performance liquid chromatography method for simultaneous determination of amino acids and biogenic amines in wine, fruit and honey.

This paper reports a new, simple, rapid and economical method for routine determination of 24 amino acids and biogenic amines in grapes and wine. No sample clean-up is required and total run time including column re-equilibration is less than 40min. Following automated in-loop automated pre-column derivatisation with an o-phthaldialdehyde, N-acetyl-l-cysteine reagent, compounds were separated on a 3mm×25cm C(18) column using a binary mobile phase. The method was validated in the range 0.25-10mg/l; repeatability was less than 3% RSD and the intermediate precision ranged from 2 to 7% RSD. The method was shown to be linear by the 'lack of fit' test and the accuracy was between 97 and 101%. The LLOQ varied between 10µg/l for aspartic and glutamic acids, ethanolamine and GABA, and 100µg/l for tyrosine, phenylalanine, putrescine and cadaverine. The method was applied to grapes, white wine, red wine, honey and three species of physalis fruit. Grapes and physalis fruit were crushed, sieved, centrifuged and diluted 1/20 and 1/100, respectively, for analysis; wines and honeys were simply diluted 10-fold. It was shown using this method that the amino acid content of grapes was strongly correlated with berry volume, moderately correlated with sugar concentration and inversely correlated with total acidity.

Validation and evaluation of a high performance liquid chromatographic method for the determination of aluminium in wine.

A new method is reported for the determination of aluminium in wine by HPLC, involving derivatisation with 8-hydroxyquinoline (oxine) in the presence of micelles resulting in the formation of a fluorescent derivative. The complex is separated on a C18 column using a mobile phase of oxine - SDS - 35% acetonitrile, in a pH 7 buffer. The method was validated in the range 0.125-2 mg/l in a synthetic wine. The method was applied to the determination of aluminium in white, rosé and red wines and results compared with those obtained by atomic absorption (GFAA). Aluminium concentrations found by HPLC in white wines were greater than those found in red wines. Further investigation using a polyphenol-enriched white wine revealed a statistically significant inverse relationship between wine polyphenol content and the aluminium concentration determined by HPLC. The method may therefore be envisaged for the determination of unbound aluminium in wine.