Comprehensive Analysis of the Substituent Distribution in Hydroxyethyl Celluloses by Quantitative MALDI‐ToF‐MS

Adden, Roland; Müller, Romy; Brinkmalm, Gunnar; Ehrler, R.; Mischnick, Petra

doi:10.1002/mabi.200600028

Cited by 21 publications

(12 citation statements)

References 28 publications

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“…There is good evidence of the monosaccharide content of commercial cellulose ethers like methylcellulose and ethylcellulose because the substituents are stable under acid hydrolysis conditions. Therefore, it has been possible to hydrolyze these cellulose ethers to monosaccharides, reduce the monosaccharides to alditols, and analyze the alditol mixture by chromatography versus authentic standards . The analysis of monosaccharide content of cellulose esters is far more difficult because esters are not stable under the conditions needed to hydrolyze the polysaccharide to monosaccharides.…”

Section: Introductionmentioning

confidence: 99%

Regioselective Esterification and Etherification of Cellulose: A Review

et al. 2011

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Deep understanding of the structure-property relationships of polysaccharide derivatives depends on the ability to control the position of the substituents around the monosaccharide ring and along the chain. Equally important is the ability to analyze position of substitution. Historically, both synthetic control and analysis of regiochemistry have been very difficult for cellulose derivatives, as for most other polysaccharide derivatives. With the advent of cellulose solvents that are suitable for chemical transformations, it has become possible to carry out cellulose derivatization under conditions sufficiently mild to permit increasingly complete regiochemical control, particularly with regard to the position of the substituents around the anhydroglucose ring. In addition, new techniques for forming cellulose and its derivatives from monomers, either by enzyme-catalyzed processes or chemical polymerization, permit us to address new frontiers in regiochemical control. We review these exciting developments in regiocontrolled synthesis of cellulose derivatives and their implications for in-depth structure-property studies.

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Section: Introductionmentioning

confidence: 99%

Regioselective Esterification and Etherification of Cellulose: A Review

et al. 2011

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“…The characterization of the substitution pattern of commercial hydroxyethyl cellulose is carried out by gas-liquid chromatography in combination with matrix assisted laser desorption ionisation time of flight mass spectroscopy after permethylation and hydrolytical chain degradation. [2,3] It is not possible to get detailed structure information of the intact polymer by means of, e.g., NMR spectroscopy. Therefore, regioselective functionalization of cellulose is a promising tool to get model substances very useful for the evaluation of structure property relationships.…”

Section: Introductionmentioning

confidence: 99%

Study on Synthesis and NMR Characterization of 2,3‐O‐Hydroxyethyl Cellulose Depending on Synthesis Conditions

Petzold‐Welcke

Kötteritzsch

Fenn³

et al. 2010

Macromolecular Symposia

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Summary:The synthesis of hydroxyethyl celluloses with regioselective functionalization in position 2 and 3 starting from triphenylmethyl (trityl) cellulose is described. The effects of reaction conditions upon both the degree of substitution and the distribution of the hydroxyethyl moieties were investigated in detail. The interest was not only focused on regioselective functionalization within the anhydroglucose unit but also on the formation of oxyethylene side chains. To avoid the formation of oxyethylene side chains, 2-(2-bromoethoxy)tetrahydropyran was used as etherifying agent in comparison with 2-bromoethanol. By acidic hydrolysis, both protecting groups -trityl at 6 position and tetrahydropyran at the hydroxyethyl substituentcan be simultaneously cleaved off. The hydroxyethyl celluloses were characterized by one-and two-dimensional NMR spectroscopy in order to determine the substitution pattern.

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“…By the introduction of the more flexible, crown-ethers resembling O -(CH 2 CH 2 - O ) n -CH 3 segments at the carbohydrate backbone, sodium complexation properties are significantly enhanced. To generate charge-controlled positive ions, propyl amine has been introduced by reductive amination and subsequently quaternized [ 7 , 8 , 10 ]. By MALDI-ToF-MS, the average hydroxyalkyl MS was constantly met for all DPs evaluated for HEMCs and HPMCs with a maximum MS of 0.17 (HE) [ 7 ] and 0.21 (HP) [ 8 ], respectively.…”

Section: Introductionmentioning

confidence: 99%

Impact of instrumental settings in electrospray ionization ion trap mass spectrometry on the analysis of O-methoxyethyl-O-methyl cellulose: a comprehensive quantitative evaluation

et al. 2022

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The hydroxyethyl substitution along and among the polymer chains of respective cellulose ethers (HEC and HEMC) can be analyzed by ESI-IT-MS after permethylation of the free OH-groups, partial hydrolysis, and mABA labeling. This method requires the correct quantification of the molar ratios of the constituents belonging to a particular degree of polymerization (DP) with respect to their numbers of MeOEt and Me groups without any discrimination along the MS analysis pathway. The influence of the chemistry on the ionization and the impact of the voltages controlling the ion transport (Cap Exit, Octopoles) and the ion storage efficiency (Trap Drive, TD) on a relative quantification were studied using binary equimolar mixtures of cellobiose with increasing number of methoxyethyl and decreasing number of methyl groups (Δ m/z 88, 2× MeOEt). No suppression effects were observed in concentration-dependent measurements. Choice of Cap Exit is especially crucial for low m/z with less MeOEt residues. An equation describing the relationship between Oct 2 DC, m/z, and TDmax (TD at maximum intensity) was established from the experimental data and applied to calculate TDmax for higher DPs (larger COS). Optimized conditions allowed to determine the correct molar ratio of binary mixtures. Measurements of overlapping m/z segments and subsequent interrelation of the data gave complete substitution profiles for MeOEt/Me celluloses in accordance with reference data. The study generally makes aware of potential erroneous quantification in ESI-IT-MS analysis using internal standards of similar chemistry or in relative quantification of analytes, even for those with related structures. Graphical abstract

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Comprehensive Analysis of the Substituent Distribution in Hydroxyethyl Celluloses by Quantitative MALDI‐ToF‐MS

Cited by 21 publications

References 28 publications

Regioselective Esterification and Etherification of Cellulose: A Review

Regioselective Esterification and Etherification of Cellulose: A Review

Study on Synthesis and NMR Characterization of 2,3‐O‐Hydroxyethyl Cellulose Depending on Synthesis Conditions

Impact of instrumental settings in electrospray ionization ion trap mass spectrometry on the analysis of O-methoxyethyl-O-methyl cellulose: a comprehensive quantitative evaluation

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