An extraction-derivatization method suitable for the analysis of biogenic amines by gas chromatography negative ion mass spectrometry.

An extraction-derivatization method suitable for the analysis of subnanogram amounts of biogenic amines in aqueous solution has been developed. The most satisfactory procedure for the analysis of these compounds was reaction with 3,5-ditrifluorobenzoylchloride (DTFMBCl) in phosphate buffer at pH 7.2 followed by extraction of the resultant amide esters into ethyl acetate. This was followed by hydrolysis of the phenolic ester functionalities by shaking the organic layer with 10 M ammonium hydroxide. The phenolic and alcoholic hydroxyl groups were then reacted with bistrimethylsilylacetamide and the trimethylsilyl-DTFMB amides were then analysed by gas chromatography/mass spectrometry in the negative ion chemical ionization mode with methane as reagent gas. The limits of detection for these derivatives was less than 1 pg and the method was readily applicable to the extraction and analysis of 0.5 ng of a given biogenic amine.