Hydroxyl radical alteration of HPLC fractionated lignin: Formation of new compounds from terrestrial organic matter

摘要

Highlights?Molecular characterization of HPLC fractionated lignin presented.?Hydroxyl radical treatment shown to significantly alter lignin fractions.?Polar components of dissolved lignin responsible for new compounds formed.AbstractReactive oxygen species (ROS) are thought to play an important, although poorly understood, role in modifying the composition of terrigenous-derived dissolved organic matter (tDOM) upon export to aquatic systems. Of the dominant ROS in natural systems, OH has been shown to substantially modify lignin under laboratory conditions, simulating processes responsible for transformation of DOM in natural waters. Utilizing high performance liquid chromatography (HPLC) in conjunction with ultrahigh resolution mass spectrometry, we examined HPLC fractionated lignin extracts in an effort to establish which fractionated components of the lignin extract were (i) most susceptible to attack by OH and (ii) most likely to be responsible for compounds observed in the DOM. The results indicate that the m