Analysis of Organic Nitrogen Compounds Using Paired Ion Chromatography. Applications to the Analysis of Coal-Derived Liquids

Abstract

Evaluation of HPLC as a possible method by which the nitrogen compounds in coal-derived liquids could be analyzed has met with mixed results. Some chromatography fractions display very different HPLC traces in methanol compared with those obtained in a MeOH-HOAc-PIC mixture, but others are insensitive to the change in eluent. HPLC of several model compounds has revealed basic nitrogen compounds generally have longer retention times in paired ion chromatography (PIC) solutions, but that some actually have shorter times. Heterocyclic nitrogen compounds all give longer retention times in PIC solution than in methanol.