Aqueous size exclusion chromatography

Kato, Yoshio

doi:10.1007/978-1-4615-7861-1_7

Cited by 6 publications

(7 citation statements)

References 33 publications

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“…Polyelectrolyte-gel adsorption can be reduced, in general, by addition of a low molar mass electrolyte to the eluant (see, for example, ref. 48). However, use of 0.1M NaNO,(aq) solution did not effect elution of any of the polymer samples within the range of calibration volumes established using the PEO standards.…”

Section: Resultsmentioning

confidence: 99%

Luminescence studies of hydrophobically modified, water-soluble polymers. I. Fluorescence anisotropy and spectroscopic investigations of the conformational behaviour of copolymers of acrylic acid and styrene or methyl methacrylate

Ebdon¹,

Hunt²,

Lucas³

et al. 1995

Can. J. Chem.

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Fluorescence spectroscopy and anisotropy measurements have been used to study a series of styrene -acrylic acid, STY-AA, and methyl methacrylate -acrylic acid, MMA-AA, copolymers in dilute methanolic and aqueous solutions. Copolymerization of either STY or MMA with AA has little effect upon the rate of intramolecular segmental motion in methanol solutions. In aqueous media, intramolecular hydrophobic aggregation occurs and restricts the macromolecular dynamics to an extent dependent upon pH, nature of the comonomer, and copolymer composition. The hydrophobic domains formed in these copolymer systems can solubilize organic guests. In this respect, STY is a more powerful modifier of AA-based polymer behaviours than is MMA. In general, the hydrophobic modification increases the solubilization power of the resultant polymer. Furthermore, the copolymers retain their solubilization capacities to higher values of pH the more hydrophobic the comonomer and the greater its content in the copolymer. The interiors of the hydrophobic aggregates reduce the mobilities of occluded guests: the microviscosities of the domain interiors depend upon the nature of the hydrophobe, pH, and copolymer composition.

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Section: Resultsmentioning

confidence: 99%

Luminescence studies of hydrophobically modified, water-soluble polymers. I. Fluorescence anisotropy and spectroscopic investigations of the conformational behaviour of copolymers of acrylic acid and styrene or methyl methacrylate

Ebdon¹,

Hunt²,

Lucas³

et al. 1995

Can. J. Chem.

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“…Ils sont dus aux nombreux groupements hydroxyles, mais aussi à une petite quantité de groupements carboxyles présents sur le gel. Ces phéno-mènes peuvent être réduits en employant des éluants capables de supprimer ou de masquer l'ionisation des groupements parasites ; des solutions salines ont souvent été proposées ainsi que de l'eau acidifiée (KATO ef al., 1980 ;KATO, 1989). Les contraintes du DEDL nécessitant l'utilisation d'éluants évaporables nous ont amené à choisir l'eau acidifiée par de l'acide acétique.…”

Section: Les Conditions Chromatographiques Les éLuantsunclassified

“…Nous nous sommes donc fixés comme objectif d'améliorer le fractionnement en utilisant la chromatographie d'exclusion stérique haute performance après une pré-séparation par ultrafiltration ; pour cela, nous avons utilisé des données sur la séparation des substances humiques (DE HAAN ef al., 1978 ;DUBIN, 1988 ;HONGVE ef al., 1996 ;MATSUBARA ef al., 1994 ;POSNER, 1963) et plus générale-ment sur les macromolécules d'origine naturelle (HEJZLAR, 1987 ;KATO ef al., 1980 ;KATO, 1989 ;RINAUDO ef al., 1991). Expérimental protocol for ultrafiltration.…”

Section: Introductionunclassified

Fractionnement et caractérisation des lixiviats de centres d'enfouissement technique de déchets ménagers: intérêt de la chromatographie liquide haute performance sur le gel d'exclusion stérique

Coupannec¹,

Péron²

2005

rseau

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L'ultrafiltration et la chromatographie d'exclusion stérique haute performance sont utilisées pour la séparation et la caractérisation des composés organiques présents dans les lixiviats de centres d'enfouissement technique de déchets ménagers. Le fractionnement de la matière organique est obtenu sur des colonnes type TSK PW, en élution eau pH 4 et eau-méthanol. La spectroscopie en UV-visible et en fluorescence, un détecteur évaporatif à diffusion de lumière sont utilisés pour la caractérisation des fractions. Cette méthode rapide de séparation associée à une multidétection permet une mise en évidence, dans les fractions issues de l'ultrafiltration, de composés organiques caractéristiques. Dans la fraction de poids moléculaires inférieurs à 1000 Daltons, trois familles sont détectées. Les substances humiques et les protéines sont les principaux groupes présents dans la fraction de poids moléculaires supérieurs à 10000 Daltons.Landfill leachates represent a source of organic pollution characterized by an important organic load, with high chemical oxygen demand in recent sanitary landfills and some organic compounds refractory to biodegradation. Several researchers have examined the organic matter in these landfill leachates. In addition to measuring parameters such as chemical and biological oxygen demands (COD and BOD) and UV-absorbance, different analytical techniques were applied: gas chromatography with flame ionization or mass detection; high performance liquid chromatography; infrared spectroscopy; nuclear magnetic resonance spectrometry; and elementary analysis. Raw leachates or samples after fractionation on Sephadex gel were characterized by ultrafiltration or adsorption on XAD resins.Conclusions from these earlier studies were as follows: - physico-chemical properties of leachates revealed not only a high organic pollution but also diversity and variability according to the age of the sanitary landfill and the climatic conditions; - gel permeation chromatography and ultrafiltration revealed two main fractions in the leachates: one with molecular weights below 1000 Daltons (Da), and another with molecular weights above 5000-10000 Da; - infrared spectroscopy and nuclear magnetic resonance spectrometry showed functional groups present in the humic and fulvic acid fractions of natural organic matter; - a varying number of peaks detected by gas chromatography with flame ionization or mass detection proved the complexity of the matrix. Few compounds were identified and quantified, with the exception of fatty acids. Moreover this technique was only applicable to molecules with low molecular weight.The purpose of the present work was to develop a new method of fractionation of organic matter in landfill leachates and to study their characterization and treatment biodegradation. Ultrafiltration, as a prefractionation step, divided the leachate into four fractions according to their molecular weight: above 10000 Da, from 10000 - 3000 Da, from 3000 - 1000 Da, and below 1000 Da. The second fractionation step was ca...

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“…The solute-support interactions are of course undesirable for the study of the molecular weight distribution of the molecules but they can be made profitable for the optimisation of their separation. These interactions were previously described [4,6,7] and it was shown that the choice of the eluent is particularly critical in aqueous size exclusion chromatography. It is not trivial to eliminate such interactions but they can be, at least, strongly reduced by judiciously choosing the eluent properties (pH, ionic strength, addition of organic co-solvent...) [7].…”

mentioning

confidence: 91%

“…These interactions were previously described [4,6,7] and it was shown that the choice of the eluent is particularly critical in aqueous size exclusion chromatography. It is not trivial to eliminate such interactions but they can be, at least, strongly reduced by judiciously choosing the eluent properties (pH, ionic strength, addition of organic co-solvent...) [7]. Sodium nitrate is often preferred for the elution of humic substances in HPSEC.…”

mentioning

confidence: 91%

Influence of secondary interactions on high performance size exclusion chromatography. Application to the fractionation of landfill leachates

et al. 2000

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Many authors undertook the chemical characterisation of the leachates generated by the municipal landfills. The review of the data of the literature (see [1]) shows that several separative and analytical techniques were primarily used i.e. the ultrafiltration, the liquid-liquid extraction, the permeation chromatography on Sephadex gels, the adsorption on Amberlite XAD resins, and the gas chromatography. This led us to use a different method: the high performance size exclusion chromatography (HPSEC).We carried out a preliminarily study [1], which showed that leachates from domestic wastes contain molecules which could be filed in two main groups according to their molecular weights: one constituted of molecules of AMW (Apparent Molecular Weight) lower than 1000 Da and the other one with molecules of AMW higher than 10000 Da. Few products of intermediate molecular weights are present. Simultaneous monitoring of the samples by UV absorbance, fluorescence and evaporative light scattering (ELSD) reveals the diversity of the physico-chemical characteristics of the separated compounds. A thorough spectrometric study [2] enabled us to validate the choice of excitation/emission couples characteristic of the substances so-called humic-type and protein-type compounds used in the first study. We also showed that the chromatographic elution of the molecules is biased by secondary interactions. So, in the present article we propose to study the influence of these interactions on chromatographic separation.The mechanism of steric exclusion is theoretically a purely entropic phenomenon, which warrants for the observed relation between the volume of elution and the hydrodynamic volume of the eluted molecule. One however notes experimental variations in retention times either due to adsorption (elution delayed) or exclusion (elution advanced). This is to say that interactions between the eluted molecules and the stationary phase modify the elution order of compounds with definite molecular weights. In aqueous solvents, very polar ionised groups are exposed at the water-soluble compounds surface and secondary enthalpic interactions are observed [3][4][5]. They are due to ion-exchange and ionexclusion effects, hydrophobic interactions and hydrogen bonds. The solute-support interactions are of course undesirable for the study of the molecular weight distribution of the molecules but they can be made profitable for the optimisation of their separation. These interactions were previously described [4,6,7] and it was shown that the choice of the eluent is particularly critical in aqueous size exclusion chromatography. It is not trivial to eliminate such interactions but they can be, at least, strongly reduced by judiciously choosing the eluent properties (pH, ionic strength, addition of organic co-solvent...) [7]. Sodium nitrate is often preferred for the elution of humic substances in HPSEC. At a 20 mM concentration in the eluent, the elution of the fulvic acids on both polymeric-and silica-based columns is weakly disturbed by the io...

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Aqueous size exclusion chromatography

Cited by 6 publications

References 33 publications

Luminescence studies of hydrophobically modified, water-soluble polymers. I. Fluorescence anisotropy and spectroscopic investigations of the conformational behaviour of copolymers of acrylic acid and styrene or methyl methacrylate

Luminescence studies of hydrophobically modified, water-soluble polymers. I. Fluorescence anisotropy and spectroscopic investigations of the conformational behaviour of copolymers of acrylic acid and styrene or methyl methacrylate

Fractionnement et caractérisation des lixiviats de centres d'enfouissement technique de déchets ménagers: intérêt de la chromatographie liquide haute performance sur le gel d'exclusion stérique

Influence of secondary interactions on high performance size exclusion chromatography. Application to the fractionation of landfill leachates

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