A comparison of the gas chromatographic and mass spectrometric properties of the pentafluoropropionyl and heptafluorobutyryl derivatives of the methyl, trifluoroethyl, pentafluoropropyl and hexafluoroisopropyl esters of twelve acidic metabolites of biogenic amines.

The gas chromatographic and mass spectrometric properties of the methyl, trifluoroethyl, pentafluoropropyl and hexafluoroisopropyl esters of the pentafluoropropionyl and heptafluorobutyryl derivatives of twelve important acidic metabolites of biogenic amines have been investigated. The optimum derivatization conditions for the different classes of metabolites have been established and the byproducts formed in some of the derivatizations have been identified. Under certain derivatizing conditions, back-exchange of deuterium in the labelled internal standards was observed. No single derivative appears to be ideally suitable for the simultaneous quantitative analysis by GC/MS of all twelve metabolites, so extracts of plasma and urine were split and a combination of the methyl or trifluoroethyl esters of the pentafluoropropionyl derivatives were used.