Hi Cemal,

To synthesis chitosan from crustaceans, follow these steps

1. Cleaning: Remove the shells from the shrimp or lobster, clean well, dry and blend it.

2. Decalcification: using aqueous HCl (3 to 5% w/v) at room temperature overnight.

3. Deproteinization: using aqueous dil. NaOH(3 to 5% w/v) at room temperature overnight or 80 to 200 oC for few hours. You will get the product CHITIN

4. Decolorization: using 0.5 % KMnO4 and Oxalic acid. (You can avoid this step if you use colourless endoskeleton such as squid gladius)

5. Deacetylation: using hot con. NaOH (40 to 50% w/v) at room temperature. Now you will get an end product CHITOSAN.

Check this links for more information:

Article Mechanochemical synthesis of chitosan submicron particles fr...

Article Synthesis and Characterization of Chitosan Nanoaggregates fr...

Article Antioxidant properties of chitosan from crab shells

Article Extraction of chitin and chitosan from local sources

Thank you.