Possibilities of Mass Spectrometry and Tandem‐Mass Spectrometry in the Analysis of Cellulose Ethers

Abstract

The investigation of the substituent pattern of cellulose and starch ethers and esters on various structural levels as in the glucosyl unit, along the polymer chain, and over the polymer molecules, still is a very challenging task.By means of mass spectrometric methods as ESI‐MS or MALDI‐TOF‐MS the composition of oligosaccharide mixtures which represent the substituent distribution in the original polymer can principally be determined. However, to obtain reliable quantitative data mass spectra must be recorded under appropriate instrumental conditions and after special sample preparation While O‐methyl/O‐methyl‐d3‐oligosaccharides give representative data with the mentioned MS techniques and FAB‐MS as well, hydroxyalkyl ethers require labelling with a quaternary ammonium tag and MALDI‐TOF‐MS to prevent discrimination of lower substituted oligosaccharides. In this way, information on the neighbourhood of glucosyl units in the polymer chain is available which – together with the monomer composition – is a valuable parameter to describe a random or a heterogeneous pattern with regions of local higher densities of substituents compared to the random model, a regular distribution, or a block‐like substituent pattern, i.e. a more clustered localisation of substiuents in the polymer chain. In addition, tandem‐mass spectrometry (ESI‐MSn) allows to gain further insight in the composition of isomeric oligosaccharide derivatives of the same m/z ratio and to calculate the complete monomer composition of methyl celluloses.

Tandem Mass Spectrometry of Tagged and Permethylated Polysaccharides

“…The challenges to polysaccharides determination are that the glycan-moiety has different chemical properties than proteins or nucleic acids (Forsberg et al, 2000;Faber et al, 2001;Lattová et al, 2005;Mischnick et al, 2005;Nielsen et al, 2010) and most of them are www.intechopen.com…”

Identification of cellulose ethers in cultural heritage by means of MALDI-TOF-MS

“…Despite identification of cellulose ethers by MALDI-TOF has been described before [46][47][48] this procedure has not been applied to the characterization of these compounds in paper-based artworks yet. Although there are several cases of characterization of cellulose ethers in cultural heritage via FTIR [49][50][51][52], wide-angle X-ray scattering (WAXD), TGA / differential thermal analysis (DTA), and differential scanning calorimetry (DSC) [53] the identification of low amounts of different types of cellulose ethers spread on cellulosic supports -with the resulting signal interference due to similar nature among adhesive and support-, has not been fully addressed yet.…”

Endoglucanase Sensitivity for Substituents in Methyl Cellulose Hydrolysis Studied Using MALDI-TOFMS for Oligosaccharide Analysis and Structural Analysis of Enzyme Active Sites

“…If the polymer is highly substituted, the enzyme may not be able to degrade it at all, and in this case more detailed information concerning the distribution pattern cannot be collected . The intact parts of the polymer may be further analyzed using fractionation and acid hydrolysis combined with for example NMR or MS analysis. , …”

“…12 The intact parts of the polymer may be further analyzed using fractionation and acid hydrolysis combined with for example NMR or MS analysis. 13,14 The extent to which the enzyme is hindered is determined by the active site structure of the enzyme. More specific information on the substitution pattern can be achieved by comparing the degradation pattern from several different endoglucanases.…”