Negative chemical ionization mass spectrometry of phenols, and their determination in acidic fractions of coal‐derived liquids

Abstract

AbstractThe use of Freon–113 as a reagent gas in the negative chemical ionization mass spectra of phenolic compounds is reported. The dominant mode of ionization is by chloride attachment producing [M + Cl]− ions. The application of this technique to the highly phenolic acid fractions from coal‐derived liquids gives spectra containing essentially only [M + Cl]− peaks. This allows relative molecular mass profiles to be obtained. The resultant complex spectra are simplified by dividing them into their homologous series components. Since this is a low‐resolution technique, absolute component identification cannot be made; but in conjunction with other analytical methods, tentative identification of series of molecules is possible. Thus, the alkyl‐substituent ranges of the different homologous series can be assessed. Comparisons between coal‐derived liquids produced under different reaction conditions are made, and composition differences detected.