Gas chromatographic determination of some biogenic amines as their pentafluorobenzoyl derivatives in the picogram range and its applicability to biological materials

Abstract

The catecholamines dopamine and noradrenaline were converted into the stable pentafluorobenzoyl (PFB) derivatives for their specific and quantitative gas chromatographic (GC) assay. This allowed their detection in the picogram range using an electron-capture detector. Acylation was performed with pentafluorobenzoyl chloride in the presence of pyridine and with acetonitrile as solvent. The structures of the PFB-catecholamines were confirmed by GC-mass spectrometry. A good separation was obtained on 5% OV-17 at 265°C. The high adsorption activity of the PFB-catecholamines could be overcome by optimizing the reaction conditions and applying special GC precautions. Linearity of the method was demonstrated for 50-500 ng of the catecholamines with detection at the picogram level. The application of the method to biological materials is demonstrated.