A useful point of comparison for TRM-0522 is the common reference material SRFA. An integrated 1 H NMR spectrum of SRFA was obtained (Figure ), run using the same parameters and instrument as was used for TRM-0522. Regions were defined in the same way as for TRM-0522, (see earlier), but a broadening of the residual water peak (4.79 ppm), led to overlap with region D (typically containing information regarding the α-proton of peptides), thus preventing accurate integration of this area. To account for this in comparison to TRM-0522, adjusted contributions of TRM-0522 are shown that exclude region D, alongside the relative contributions of SRFA (Table ). Two key pieces of information can be observed from this comparison. Firstly, there is significantly more material that contains aromatic hydrogens in SRFA than in TRM-0522 (10 vs 1 % respectively). This is typically associated with humic and fulvic substances, as well as lignin.