6-01: NMR high-throughput screening of hydrolysates for determination of sugar release

Sugars in biomass are released through the process of hydrolysis where by the biomass is subjected to hot water and acidic conditions.  The current standard practice to measure the sugar content in the liquid hydrolysate is with HPLC which can take an hour for analysis of a single sample.  Simple ¹H NMR screening methods are able to detect the sugar components in under 5 minutes making this an attractive method for high-throughput screening.  Many NMR sugar signals can be observed in the region from 3-4ppm but the overlapping peaks make simple integration techniques impossible. To extract useful information from this region, multivariate statistical methods are required.  In this work we present the results on a set of hyrolysates that were acquired under neutral pH at 600MHz in a high-sensitivity Bruker Cryoprobe.  Each NMR spectrum was acquired with 8 scans in less than 2 minutes making this technique an ideal system for high throughput analysis.  Partial Least Squares prediction has been applied to build models that accurately predict sugar concentrations when compared with HPLC results.  One of the advantages of the NMR based method is that sugar degradation products such as HMF and furfural can also be detected and quantified along with the sugars.