Chemometric prediction of alginate monomer composition: A comparative spectroscopic study using IR, Raman, NIR and NMR

Salomonsen, Tina; Jensen, Henrik Max; Stenbæk, D.; Engelsen, Søren Balling

doi:10.1016/j.carbpol.2007.10.022

Cited by 85 publications

(48 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For most of the samples, the SD within triplicates is low (SD <0.1, Table 3). The SD of the M/G ratios reported in Table 3 for, sample sets 1 and 2, correlate well with previously published [5] SD for M/G ratios determined on commercially available alginate samples. The differences between sample sets 1 and 2 are small for most samples (Table 3), only samples 15 and 20 show differences in the M/G ratios that are larger than 0.1.…”

Section: Establishing a General Protocolsupporting

confidence: 77%

“…For T 1 measurements of signals in the anomeric region of the 1 H-NMR spectra an inversion M/G ratios determined by FTIR. [5] Viscosity (mPa·s) determined on 1% solutions at 20…”

Section: Nmr Spectroscopymentioning

confidence: 99%

“…Therefore, access to methods for accurate determination of the monomer composition or M/G ratio is important. The determination of this ratio is usually done by IR, [5 -7] NMR, [8 -12] Raman [5] or near IR [5] spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Application of diffusion‐edited NMR spectroscopy for selective suppression of water signal in the determination of monomer composition in alginates

Vilén

Klinger²,

Sandström

2011

Magnetic Reson in Chemistry

View full text Add to dashboard Cite

Alginate is a linear copolymer of 1-4 linked β-D-mannuronic acid (M) and 1-4 linked α-L-guluronic acid (G). The physical properties of these polysaccharides such as gel properties and viscosity are largely correlated to the monomer composition (M/G ratio), the sequence of the polymer and the molecular weight. Determination of the M/G ratio is therefore important and NMR spectroscopy is among the most common methods used to accurately obtain this ratio. Instead of using time consuming, possibly sample altering, acid hydrolysis to reduce the viscosity of the alginate sample prior to analysis, samples of low concentrations can be used. However, this results in a water peak in the NMR spectrum that is several orders of magnitude larger than the alginate signals and water suppression is required. In this article, a diffusion-edited NMR experiment that suppresses the water peak while retaining the signals of interest has been used to enable correct M/G ratio determination. This approach exploits the difference in translational diffusion between the larger alginate molecules and the smaller water molecules. Using this method, the monomer composition of 20 different alginate powders was determined. The diffusion parameters were optimized to allow measurement for samples covering a large range of M/G ratios and viscosities. Thus, such method should be useful for analyzing large numbers of unknown alginate samples using, for example, automation procedures.

show abstract

Section: Establishing a General Protocolsupporting

confidence: 77%

“…For T 1 measurements of signals in the anomeric region of the 1 H-NMR spectra an inversion M/G ratios determined by FTIR. [5] Viscosity (mPa·s) determined on 1% solutions at 20…”

Section: Nmr Spectroscopymentioning

confidence: 99%

See 1 more Smart Citation

Application of diffusion‐edited NMR spectroscopy for selective suppression of water signal in the determination of monomer composition in alginates

Vilén

Klinger²,

Sandström

2011

Magnetic Reson in Chemistry

View full text Add to dashboard Cite

show abstract

“…Bands around 1150-810 cm -1 are representative of pyranose skeleton modes. 54,[60][61][62] The -C-C-stretching vibrations of mannuronic and gluluronic units are pointed out around 1095 cm -1 . 63 This band is overlapping with the band corresponding to -C-O-stretching, as shown in the secondderivative spectra, with two bands well defined at 1132 and 1095 cm -1 .…”

Section: One-dimensional Ft-ir Analysismentioning

confidence: 98%

Study on antibacterial alginate-stabilized copper nanoparticles by FT-IR and 2D-IR correlation spectroscopy

Díaz-Visurraga¹,

Daza²,

Pozo³

et al. 2012

IJN

110

View full text Add to dashboard Cite

Background:The objective of this study was to clarify the intermolecular interaction between antibacterial copper nanoparticles (Cu NPs) and sodium alginate (NaAlg) by Fourier transform infrared spectroscopy (FT-IR) and to process the spectra applying two-dimensional infrared (2D-IR) correlation analysis. To our knowledge, the addition of NaAlg as a stabilizer of copper nanoparticles has not been previously reported. It is expected that the obtained results will provide valuable additional information on: (1) the influence of reducing agent ratio on the formation of copper nanoparticles in order to design functional nanomaterials with increased antibacterial activity, and (2) structural changes related to the incorporation of Cu NPs into the polymer matrix. Methods: Cu NPs were prepared by microwave heating using ascorbic acid as reducing agent and NaAlg as stabilizing agent. The characterization of synthesized Cu NPs by ultraviolet visible spectroscopy, transmission electron microscopy (TEM), electron diffraction analysis, X-ray diffraction (XRD), and semiquantitative analysis of the weight percentage composition indicated that the average particle sizes of Cu NPs are about 3-10 nm, they are spherical in shape, and consist of zerovalent Cu and Cu 2 O. Also, crystallite size and relative particle size of stabilized Cu NPs were calculated by XRD using Scherrer's formula and FT from the X-ray diffraction data. Thermogravimetric analysis, differential thermal analysis, differential scanning calorimetry (DSC), FT-IR, second-derivative spectra, and 2D-IR correlation analysis were applied to studying the stabilization mechanism of Cu NPs by NaAlg molecules. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of stabilized Cu NPs against five bacterial strains (Staphylococccus aureus ATCC 6538P, Escherichia coli ATCC 25922 and O157: H7, and Salmonella enterica serovar Typhimurium ATCC 13311 and 14028) were evaluated with macrodilution, agar dilution plate count, and well-diffusion methods. Results: On the basis of the semiquantitative analysis, there was a direct correlation between the reducing agent ratio and the percentage of zerovalent Cu. This was confirmed with the statistical analysis of population of Cu NPs from TEM micrographs. At lower reducing agent ratios, two phases coexist (Cu 2 O and zerovalent Cu) due to incomplete reduction of copper ions by the reducing agent; however, at higher reducing agent ratios, the Cu NPs consist mainly of zerovalent Cu. Crystallite size and relative particle size of stabilized Cu NPs showed considerable differences in results and tendencies in respect to TEM analysis. However, the relative particle size values obtained from FT of XRD data agreed well with the histograms from the TEM observations. From FT results, the relative particle size and reducing agent ratio of stabilized Cu NPs showed an inverse correlation. The incomplete reduction of copper ions at lower reducing agent ratios was also confirmed by DSC studies. FT-IR and 2D-IR correl...

show abstract

“…[3 -5] Vibrational spectroscopy has been applied for the characterization of alginic acid samples and block fractions, and it was found that homopolymannuronic and homopolyguluronic acids fraction presented characteristic bands in FT-IR spectra. [6 -8] According to Pereira et al [9] alginates can be identified by Raman spectroscopy, and Salomonsen et al [10] reported the application of IR, Raman, and NIR spectroscopies and chemometrics for the determination of M/G ratio in alginic acid. Recently, the use of salts of alginic acid as model compounds in the analysis by Raman spectroscopy of biofilm matrix has been reported.…”

Section: Introductionmentioning

confidence: 99%

Characterization of sodium alginate and its block fractions by surface‐enhanced Raman spectroscopy

Campos‐Vallette

Chandía

Clavijo

et al. 2010

J Raman Spectroscopy

View full text Add to dashboard Cite

The surface-enhanced Raman scattering (SERS) of sodium alginates and their hetero-and homopolymeric fractions obtained from four seaweeds of the Chilean coast was studied. Alginic acid is a copolymer of β-D-mannuronic acid (M) and α-L guluronic acid (G), linked 1 → 4, forming two homopolymeric fractions (MM and GG) and a heteropolymeric fraction (MG). The SERS spectra were registered on silver colloid with the 632.8 nm line of a He-Ne laser. The SERS spectra of sodium alginate and the polyguluronate fraction present various carboxylate bands which are probably due to the coexistence of different molecular conformations. SERS allows to differentiate the hetero-and homopolymeric fractions of alginic acid by characteristic bands. In the fingerprint region, all the poly-D-mannuronate samples present a band around 946 cm −1 assigned to C-O stretching, and C-C-H and C-O-H deformation vibrations, a band at 863 cm−1 assigned to deformation vibration of β-C 1 -H group, and one at 799-788 cm −1 due to the contributions of various vibration modes. Poly-L-guluronate spectra show three characteristic bands, at 928-913 cm −1 assigned to symmetric stretching vibration of C-O-C group, at 890-889 cm −1 due to C-C-H, skeletal C-C, and C-O vibrations, and at 797 cm −1 assigned to α C 1 -H deformation vibration. The heteropolymeric fractions present two characteristic bands in the region with the more important one being an intense band at 730 cm −1 due to ring breathing vibration mode.

show abstract

Chemometric prediction of alginate monomer composition: A comparative spectroscopic study using IR, Raman, NIR and NMR

Cited by 85 publications

References 30 publications

Application of diffusion‐edited NMR spectroscopy for selective suppression of water signal in the determination of monomer composition in alginates

Application of diffusion‐edited NMR spectroscopy for selective suppression of water signal in the determination of monomer composition in alginates

Study on antibacterial alginate-stabilized copper nanoparticles by FT-IR and 2D-IR correlation spectroscopy

Characterization of sodium alginate and its block fractions by surface‐enhanced Raman spectroscopy

Contact Info

Product

Resources

About