This study was designed to apply the method of field ionization mass spectrometry (FIMS) for the analysis of direct coal liquefaction process-stream samples. The FIMS method was shown to have a high potential for application to direct coal liquefaction-derived samples in a Phase 1 project in this program. In this Phase 3 project, the FIMS method was applied to a set of samples produced in HRI bench-scale liquefaction Runs CC-15 and CC-16. FIMS was used to obtain the molecular weight profile of the samples and to identify specific prominent peaks in the low end (160--420 Da) region of the molecular weight profile. In the samples examined in this study, species were identified which previously were recognized as precursors to the formation of high molecular weight structures associated with the formation of coke in petroleum vacuum gas oils.