High‐resolution mass spectrometric study of weathered road tars

Abstract

Fractions of road tars of coke‐oven and vertical retort origin were examined by high‐resolution mass spectrometry before and after exposure to road conditions. Molecular formulae and relative concentrations were determined for eleven series of peaks. A progressive increase in the proportion of components of high molecular weight (> mass 200) was indicated with exposure to road conditions. In the high molecular‐weight range, the heterocyclic structures containing oxygen showed larger increases than the polynuclear aromatic hydrocarbons.