Coal Tar Analysis by Lc/ms

The production of liquids from coal gives rise to complex intermediates which require detailed analysis to understand the processes occurring and to make effective use of the products. Analysis has hitherto been based on structural parameters from NMR methods (1) to give the average characteristics of the sample, supplemented by molecular information from GC and GC/MS. The gas chromatographic approach to molecular information is often hampered by lack of volatility and is generally limited to aromatic systems of five or six condensed r i n g s with molecular weights up to about 300 ( 2 ) . For samples with number average molecular weights over 300, the molecular information available through GC/MS describes less than half of the compounds present. To improve this situation we have investigated LC in conjunction with mass spectrometry for the analysis of coal tar.