2022 Annual Meeting
Optimizing the Use of N,N-Dimethylcyclohexylamine (DMCHA) for the Extraction of Betulin from Birch Bark
The use of the organic compound Betulin for the production of biopolymers and in feedstocks for other biological applications has highlighted its value as a naturally occurring molecule. The outer layer of birch bark has been found to be rich in betulin, making the extraction of this valuable compound from bark a worthwhile endeavor. Current methods of betulin extraction typically involve the use of hazardous solvents, which makes extraction processes more energy intensive and harmful to the environment. The use of Switchable Hydrophilicity Solvents (SHS) presents a promising alternative to traditional extraction methods. This class of solvents can reversibly switch between two radically different forms using an external trigger. This study will examine the use of the well-characterized SHS N,N-Dimethylcyclohexylamine (DMCHA), for the extraction of betulin from birch bark samples. DMCHA is an SHS which switches from a hydrophobic state to hydrophilic state with the addition of carbon dioxide and water. Additionally, its polarity within the hydrophobic state is tunable based on temperature. In its hydrophobic form, DMCHA can be used to extract certain valuable compounds like betulin from birch bark. In its hydrophilic state, betulin will be forced out of solution. This study aims to optimize the extraction of betulin from birch bark by varying the switching parameters of DMCHA with both CO2 and temperature switching.
Through the use of liquid chromatography and mass spectroscopy, the concentrations of betulin and other desired compounds in DMCHA extractions from birch bark were determined. Additionally, spectrophotometry was utilized to provide the total phenolic contents of the extractions. This study found that the selectivity of betulin and other desirable compounds increases when DMCHA is fully switched into its hydrophilic state after an extraction in its hydrophobic state. Furthermore, the use of high water to DMCHA ratios during the CO2 switch has been found to increase the selectivity of recovered desirable compounds.