Microscale alkaline nitrobenzene oxidation method for high-throughput determination of lignin aromatic components

The nitrobenzene oxidation method is widely used for structural analysis of lignin. However, the conventional nitrobenzene oxidation method has several drawbacks including the requirement of a sizeable amount of sample material and the rather slow completion of the reaction process. In this paper, we describe a microscale nitrobenzene oxidation method using deuterium-labeled vanillin and syringaldehyde as internal standards. Using this method, we show that the microscale nitrobenzene oxidation method realized high-throughput determination of lignin components using a small amount of sample, i.e. 10 mg per reaction, and high reproducibility. Due to the small sample sizes, the oxidation reaction and extraction steps of a number of samples can be completed in parallel, thus enabling us to process more than 40 samples per day.