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Chitin characterization by SEM, FTIR, XRD, and 13 C cross polarization/mass angle spinning NMR
Author(s) -
Cárdenas Galo,
Cabrera Gustavo,
Taboada Edelio,
Miranda S. Patricia
Publication year - 2004
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.20647
Subject(s) - chitin , shrimp , nuclear chemistry , magic angle spinning , fourier transform infrared spectroscopy , demineralization , prawn , materials science , squid , sodium hydroxide , orthorhombic crystal system , analytical chemistry (journal) , chemistry , crystallography , nuclear magnetic resonance spectroscopy , stereochemistry , chemical engineering , biology , chromatography , organic chemistry , chitosan , fishery , crystal structure , composite material , enamel paint , engineering
The full characterization of chitin obtained from squid, shrimp, prawn, lobsters, and king crab is reported. Elemental analysis, including metals such as Ca, Mg, Zn, Cd, Hg, Cr, Mn, Cu, and Pb, was performed, which is quite relevant because the skeleton composition is slightly different for each species. The morphology was studied by means of TEM and their compositions were determined by energy‐dispersive X‐ray analysis. 13 C cross polarization/magic angle spinning NMR was applied to determine the chemical shift of all the carbons and the difference between them. Chitin was isolated by using chemical methods, alternating hydrochloric acid and sodium hydroxide. The α‐chitin from shrimp, prawn, lobsters, and king crabs showed two signals at 73.7 and 75.6 ppm. Meanwhile, the β‐chitin from squid exhibited one signal at 75.2 ppm. FTIR studies were used to analyze α‐chitin from shrimp and β‐chitin from squid. The α‐chitin exhibited amide I vibration modes at 1660 and 1627 cm −1 , whereas the β‐chitin showed one band at 1656 cm −1 . X‐ray diffraction showed that α‐chitin is orthorhombic ( a = 4.74 Å, b = 18.86 Å, and c = 10.32 Å) and β‐chitin had a monoclinic dihydrated form ( a = 4.80 Å, b = 10.40 Å, c = 11.10 Å, and β = 97°). © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1876–1885, 2004