Quantitative analysis of mixtures of alkylphenol isomers by fluorine-19 magnetic resonance spectroscopy

Abstract

To develop a convenient method for determining o- and p-alkylphenols in mixtures of these isomers the application of the nuclear magnetic resonance technique has been investigated. The mixed alkylphenols were converted into the corresponding trifluoroacetates and the fluorine magnetic resonance spectra measured. The differences in chemical shifts between the alkylphenol isomers were large enough to permit their quantitative determination by comparing the relative intensities of the resonance pairs. The standard deviation for the peak height measurement method was 0·34 per cent. The method can be applied satisfactorily to the determination of o- and p-alkyl-phenols in which branching of the alkyl chains is slight.