Review published: “New developments in the analysis of partially acetylated chitosan polymers and oligomers“

Finally, after a long time, the book entitled “Chitin and Chitosan: Properties and Applications” has been released in the Wiley Series in “Renewable Resources”. There has been a surprisingly long list of new books on chitin and chitosan recently, but we trust that this one, edited by Profs. Lambertus van den Broek and Carmen Boeriu from Wageningen University in the Netherlands, will stand out in terms of quality and comprehensiveness. The editors had asked us to contribute a chapter on newly emerging tools for the analysis of chitosans, a task that was taken on by our post-doctoral researchers Dr. Stefan Cord‐Landwehr, Dr. Anna Niehues, and Dr. Jasper Wattjes, in collaboration with Prof. Bruno Moerschbacher. In this chapter, we briefly present the established gold standards for the analysis of the degree of polymerisation (DP), fraction of acetylation (FA), and dispersity in DP (ÐDP), and we describe in more detail the emerging techniques for the analysis of the pattern of acetylation (PA) and the dispersity in FA (ÐFA) of chitosan polymers. We also briefly present the established methods, and describe in more detail the newly emerging mass spectrometric tools for the structural analysis of partially acetylated chitosan oligomers (paCOS). Today, quantitative mass spectrometric sequencing allows the full structural description of paCOS mixtures, and this is also a prerequisite for enzymatic / mass spectrometric fingerprinting analyses of chitosan polymers. In the past, the development of reliable analytical methods for DP and FA has paved the way from first to second generation chitosans. Similarly, the current development of tools for PA analysis is laying the path towards future’s third generation chitosans. And we predict that analysis of ÐDP, which is long possible but has not yet achieved the attention it deserves, and of ÐFA may turn out to be crucial for the step towards fourth generation chitosans.