Size-exclusion chromatography of technical lignins in dimethyl sulfoxide/water and dimethylacetamide

Ringena, Okko; Lebioda, Sascha; Lehnen, Ralph; Saake, Bodo

doi:10.1016/j.chroma.2005.10.037

Cited by 71 publications

(89 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In fact, the standards soluble in DMSO, pullulan, poly(ethylene glycol), poly(methyl methacrylate),22, 36, 37 are linear polymers with hydrodynamic volumes, and therefore elution behavior, that is rather incomparable to the more compact lignin molecules. A contribution of possible non‐SEC separation mechanisms, besides interaction of the lignin with the column packing, must be considered because branched macromolecules have a general tendency of being delayed by anchoring in the pores of SEC packing.…”

Section: Resultsmentioning

confidence: 99%

“…However, applying this calibration approach shows that the hydrodynamic radii of lignin and PSS molecules, which are the basis of the SEC elution behavior, are not sufficiently comparable. This difference results from the different molecular structure and its arrangement in solution and causes considerable deviations between the true lignin molar mass and the values obtained according to the calibration approach 22. Generally, the molar mass determined by SEC with PSS standard calibration leads to significantly underestimated molar mass values compared with those obtained by small‐angle X‐ray (SAXS) and neutron (SANS) scattering techniques 23.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Getting Closer to Absolute Molar Masses of Technical Lignins

et al. 2018

View full text Add to dashboard Cite

Determination of molecular weight parameters of native and, in particular, technical lignins are based on size exclusion chromatography (SEC) approaches. However, no matter which approach is used, either conventional SEC with a refractive index detector and calibration with standards or multi‐angle light scattering (MALS) detection at 488 nm, 633 nm, 658 nm, or 690 nm, all variants can be severely erroneous. The lack of calibration standards with high structural similarity to lignin impairs the quality of the molar masses determined by conventional SEC, and the typical fluorescence of (technical) lignins renders the corresponding MALS data rather questionable. Application of MALS detection at 785 nm by using an infrared laser largely overcomes those problems and allows for a reliable and reproducible determination of the molar mass distributions of all types of lignins, which has been demonstrated in this study for various and structurally different analytes, such as kraft lignins, milled‐wood lignin, lignosulfonates, and biorefinery lignins. The topics of calibration, lignin fluorescence, and lignin UV absorption in connection with MALS detection are critically discussed in detail, and a reliable protocol is presented. Correction factors based on MALS measurements have been determined for commercially available calibration standards, such as pullulan and polystyrene sulfonate, so that now more reliable mass data can be obtained also if no MALS system is available and these conventional calibration standards have to be resorted to.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Getting Closer to Absolute Molar Masses of Technical Lignins

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Two SEC methods are most commonly employed for characterizing lignins and sulfonated lignins. One is based on an alkaline mobile phase in combination with a hydrophilic stationary phase, while the other is based on the use of THF as the mobile phase combined with polystyrene-based packing materials [9]. Methods where salts, such as lithium bromide or lithium chloride, are present in DMSO/water or dimethylacetamide (DMAc) eluents are also in use [9], as are methods where phosphate/DMSO/SDS buffer is used as a mobile phase [10,11] or where an aqueous mobile phase containing lithium bromide is used in combination with tetrapentyl-ammonium-bromide [12].…”

Section: Secmentioning

confidence: 99%

Analytical methodology for sulfonated lignins

Brudin¹,

Schoenmakers²

2010

J of Separation Science

View full text Add to dashboard Cite

There is a significant need to characterize and classify lignins and sulfonated lignins. Lignins have so far received a good deal of attention, whereas this is not true for sulfonated lignins. There is a clear demand for a better understanding of sulfonated lignins on a chemical as well as physical level. Many of the analytical methods have been developed with different goals in mind, for example, detection of sulfonated lignins in pulp-mill effluents, elucidation of structural changes in lignosulfonates during a pulping process, or identification of properties that may affect a formulation when sulfonated lignins are used as a dispersant. When sulfonated lignins are used in industrial applications, analytical data obtained using different techniques may be necessary to enable prediction of their behavior in the target application. In the present review, a critical discussion of established and promising analytical techniques for the characterization of sulfonated lignins is presented.

show abstract

“…Fellegi et al [18] investigated chemical oxygen demand (COD) of lignin in non-wood delignification black liquors and their SEC fractions obtained in a DMFwater mobile phases. Technical lignins -spent sulfite liquor samples and lignosulfonate fractions obtained by ultrafiltration -were analyzed using SEC in dimethyl sulfoxide/water/lithium bromide and dimethylacetamide/lithium chloride by Ringenaa et al [19]. Their results indicated that both analytical systems under investigation were well suited for the analysis of technical lignin.…”

Section: Introductionmentioning

confidence: 98%

Characterization of Klason lignins by reversed-phase high-performance liquid chromatography using wide-pore octadecylsilica and stepwise gradients of dimethylformamide in water

et al. 2006

View full text Add to dashboard Cite

RP-HPLC using stepwise gradients of N,N-dimethylformamide (DMF) in a phosphate-buffered (pH 3.00) aqueous mobile phase and a wide-pore (30 nm) octadecylsilica column has been applied to the analysis of a variety of lignins--organocell lignin, dioxane lignin, Björkman lignin, and Klason lignins from both softwoods and hardwoods, respectively, in order to demonstrate the usefulness of the approach for their characterization. Tandem combination of spectrophotometric diode array detection and fluorimetric detection was used to acquire more detailed information about the chromatographic behavior of lignins. The results show that a ten-step gradient can reveal distinct features of lignins and humic substances. Combination of good solvating properties of DMF for lignins together with a wide-pore RP sorbent improves surface interactions of the analytes and suppresses the influence of size exclusion effects. Thus it provides reproducibility of characterization profiles and robustness of the method. The calculated repeatability of the retention time of selected peaks was +/- 0.46% RSD. The reproducibility of the data within one week (set of seven data) was +/- 1.1% RSD. These data are also representative of the other well-shaped peaks of analyzed substances.

show abstract

Size-exclusion chromatography of technical lignins in dimethyl sulfoxide/water and dimethylacetamide

Cited by 71 publications

References 21 publications

Getting Closer to Absolute Molar Masses of Technical Lignins

Getting Closer to Absolute Molar Masses of Technical Lignins

Analytical methodology for sulfonated lignins

Characterization of Klason lignins by reversed-phase high-performance liquid chromatography using wide-pore octadecylsilica and stepwise gradients of dimethylformamide in water

Contact Info

Product

Resources

About