Measuring the Purity of Chitin with a Clean, Quantitative Solid-State NMR Method

Chitin is a versatile biopolymer which can be extracted directly from biomass and used for the preparation of high value materials, but such materials often require high purity chitin. However, complete removal of proteinaceous material from chitin, which is obtained from biomass sources, can be difficult to determine. Here we report a quick, nondestructive method to measure chitin content using solid-state multiCP C-13 NMR, which requires only 105 min and allows for recovery of the sample. A calibration curve was constructed from spectra of mass-based mixtures of commercial chitin and bovine serum albumin protein. This allowed for the quantification of chitin content (and therefore purity) in both chitinous biomass and extracted chitin samples in a quick, clean, nondestructive manner that agreed with measurements made by the method of Black and Schwartz, within the error of each of the methods.