Versatile acid base sustainable solvent for fast extraction of various molecular weight chitin from lobster shell

Abstract

Deep eutectic solvent (DES) prepared from choline chloride and four organic acid were evaluated for the extraction of chitin from lobster shell. It was found that the purity of chitins extracted with DESs was related to acid used. Purity of chitin extracted with choline chloride-malonic acid was the highest. Chitins extracted through DES treatment results in various molecular weight, which is associated with type of acid and temperature used during the treatment. For instance, chitin produced by malonic acid at 50 °C and 100 °C results in molecular weight of 312 KDa and 199 KDa respectively, whereas it extracted with malic acid at 100 °C results in 91 KDa. The physicochemical properties of chitins were characterized by FTIR, XRD, TG and SEM. Moreover, the CaCO₃ was successfully converted into levulinic acid calcium salt which could be used as calcium supplement.

Keywords: Acid base deep eutectic solvents; Calcium carbonate (PubChem CID: 10112); Calcium levulinate (PubChem CID: 11578); Chitin; Choline chloride (PubChem CID: 6209); Copper sulfate (PubChem CID: 24462); Ethanol (PubChem CID: 702); Hydrochloric acid (PubChem CID: 313); Hydrogen peroxide (PubChem CID: 784); Lactic acid (PubChem CID: 612); Levulinic acid (PubChem CID: 11579); Lithium chloride (PubChem CID: 433294); Lobster shell; Malic acid (PubChem CID: 525); Molecular weight; N,N-Dimethylacetamide (PubChem CID: 31374); Sodium hydroxide (PubChem CID: 14798).