Ion-attachment mass spectrometry (LAMS) is a technique used for measuring easily ionized organic compounds in a non-fragmenting mode by softly attaching a Li+ or another type of alkaline ion to the gaseous molecule. In this study, a prototype device for Li+ IAMS is developed for real-time quantitative monitoring of the vapor produced from thennochemical conversion of coal. Simulated tar vapor containing a suite of aromatics and the real vapor produced from the pyrolysis of coal are monitored by IAMS with a Li+ source. It is confirmed that both the simulated and real vapors are ionized without undergoing fragmentation and the sensitivities of these detected aromatic molecules are similar to one another. In addition, when the feeding rate of the coal sample is changed from 0.5 to 1.0 g/min, the peak intensities increase nearly twice as much. These results show the possibility of applying IAMS to the quantitatively monitoring of coal -derived volatiles. (C) 2016 Elsevier B.V. All rights reserved.