(191b) Separation of Chitin from Shrimp Shells using Functional Ionic Liquids

Chitin, the liner chain of (1, 4)-linked-2-acetylamido-2-deoxy-β-D-glucose, is the second most abundant natural polymer mostly from shrimp and crab shells in the industry.^[1] Chitin and its derivates are biodegradable, nontoxic and chemical stable, which have been widely applied in the medicine, agriculture, textile industries and other related fields.^[2] The traditional method of preparing chitin needs repeated acid and alkali treatment to remove protein and calcium carbonate and high-water consumption to wash the products. Obviously, the method leads to serious environment pollution and large water cost. Several approaches, such as ionic liquids extraction, enzymatic reaction or microbial fermentation, have been reported to solve above problems. Those approaches still have defects of the high cost, low purity and long time. Hence, it is meaningful to develop an efficient, simple and green strategy of chitin synthesis from shrimp shells.

Herein, we report a green and simple method to prepare chitin using choline-based ionic liquids (ILs) from shrimp shells in one step. The used IL could remove the protein and calcium carbonate, simultaneously. The type of the IL, experiment temperature and time played key roles in the process. Under optimal conditions, the chitin with 92 % purity was obtained, and the yield was up to 78 %. The reason for calcium carbonate and protein removal was the different roles of the cation and anion in the used IL. The proposed method provides a promising alternation of chitin preparation in the industry.

Key words: shrimp shells, chitin, ionic liquids

Acknowledgments

This work was supported financially by National Natural Scientific Fund of China (No.21476234, No.21506231).

References

[1] G. Cárdenas, G. Cabrera, E. Taboada, S. P. Miranda, Journal of Applied Polymer Science 2004, 93: 1876-1885.

[2] C. E. Blank, R. W. Parks, N. W. Hinman, Journal of Applied Phycology 2016, 28: 2753-2766.