Despite several decades of analytical investigations, the elucidation of the complete molecular structure of lignin remains a challenge. State of the art analytical techniques such as advanced NMR techniques have been useful tools to propose global structural motifs based on inter-unit linkage but still lack the proficiency to discerning structural populations with complete linkage sequences. Here, we present a facile approach by MALDI-ToF MS to discern molecular populations, and reveal detailed molecular structures in spruce milled wood lignin. Unique structural features of relevance to native lignin structure are reported.