The Estimation of Primary Aromatic Amines and Other Basic Nitrogen Compounds in Some Coal Liquefaction Products

The estimation of primary aromatic amines (PAA) and other basic nitrogen compounds in coal liquefaction products is described. Aqueous acid extraction was used to isolate basic nitrogen fractions which were analyzed by gas chromatography (GC) and mass spectrometry (MS). Selective chemical derivatization in conjunction with single-ion GC-MS was used to distinguish between the PAA and the isomeric aza heterocycles. The relative merits of the proprietary methylating reagent ‘Methyl-8’ (dimethylformamide dimethylacetal) and a more conventional fluoroacylating reagent for the selective derivatization of PAA are evaluated. Quantitative aspects of the analyses are discussed.