High-performance Exclusion Research Articles

Multi-C-C/C-N-Coupled Light-Emitting Aliphatic Terpolymers: N-H-Functionalized Fluorophore Monomers and High-Performance Applications.

To circumvent costly fluorescent labeling, five nonconventional, multifunctional, intrinsically fluorescent aliphatic terpolymers (1-5) have been synthesized by C-C/C-N-coupled, solution polymerization of two non-emissive monomers with protrusions of fluorophore monomers generated in situ. These scalable terpolymers were suitable for sensing and high-performance exclusion of CuII , logic function, and bioimaging. The structures of the terpolymers, in situ attachment of fluorescent monomers, aggregation-induced enhanced emission, bioimaging ability, and super adsorption were investigated by 1 H and 13 C NMR, EPR, FTIR, X-ray photoelectron, UV/Vis, and atomic absorption spectroscopy, thermogravimetric analysis, high-resolution transmission electron microscopy, dynamic light scattering, solid-state fluorescence, fluorescence imaging, and fluorescence lifetime measurements, as well as by isotherm, kinetics, and thermodynamic studies. The geometries and electronic structures of the fluorophores and the absorption and emission properties of the terpolymers were examined by DFT, time-dependent DFT, and natural transition orbital analyses. For 1, 2, and 5, the limits of detection were determined to be 1.03×10-7 , 1.65×10-7 , and 1.77×10-7 m, respectively, and the maximum adsorption capacities are 1575.21, 1433.70, and 1472.21 mg g-1 , respectively.

Fluorescent Terpolymers via In Situ Allocation of Aliphatic Fluorophore Monomers: Fe(III) Sensor, High‐Performance Removals, and Bioimaging

Herein, purely aliphatic intrinsically fluorescent terpolymers, i.e., 1 and 2, are synthesized through one-pot solution polymerization via N-H functionalized and multi C-C/C-N coupled in situ protrusion of fluorescent monomers using two nonemissive monomers. These scalable terpolymers are suitable for highly selective Fe(III) sensing, high-performance exclusion of Fe(III), logic function and the imaging of normal mammalian Madin-Darby canine kidney and human osteosarcoma cancer cell lines. The structures of terpolymers, in situ attachment of fluorescent monomers, clusteroluminescence, adsorption-mechanism, and cell-imaging abilities are understood via unadsorbed and/or adsorbed microstructural analyses using 1 H/13 C NMR, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, UV-vis spectroscopy, atomic absorption spectroscopy, thermogravimetric analysis, high-resolution transmission electron microscopy, dynamic light scattering, fluorescence imaging, and fluorescence lifetime. The geometries, electronic structures, location of fluorophores, and singlet-singlet absorption and emission of terpolymers are examined using density functional theory (DFT) and time-dependent DFT. For the precise identification of fluorophores, transition from occupied natural transition orbitals (NTOs) to unoccupied NTOs is computed. For 1/2, limit of detection (LOD) values and adsorption capacities are 6.0 × 10-7 /8.0 × 10-7 m and 147.82/120.56 mg g-1 at pHi = 7.0 and 303 K, respectively. The overall properties of 1 are more advantageous compared to 2 in sensing, cell imaging, and adsorptive exclusion of Fe(III).

DEVELOPMENT OF METHODS FOR OBTAINING POLYSACCHARIDES FROM BIRCH LEAVES (BETULA PENDU-LA ROTH., BETULA PUBESCENS EHRH.)

The development of a complex technique for the extraction and purification of polysaccharides from birch leaves (Betula pendula Roth.,Betula pubescens Ehrh.) (PSfB) was the purpose of this study. The following characteristics were used as criteria for evaluating the effect of the parameters studied on the production of target substances: yield of PSfB (gravimetric method), protein content (spectrophotometric method), molecular weight distribution (high performance exclusion chromatography) and degree of purification from low molecular weight impurities (LMWI) (IR) spectroscopy).During the experiment, the optimal parameters were determined at various stages of obtaining the PSfB: degree of raw materials grinding – 1.2–3 mm, pH of the extractant (purified water with pH=7), the ratio of raw materials : extractant (1 : 20), extraction temperature (50 °C), temperature and degree of evaporation (50 °C; 4 times), the ratio of concentrate : ethanol (1 : 3) and the method of purification from the LMWI (ultrafiltration).The result of this work is an optimized method for obtaining PSfB, allowing to achieve high yield without loss of product quality (minimum allowable content of low molecular weight impurities with the highest content of high molecular weight fractions).This technique is the basis for the development of laboratory regulations for obtaining an active pharmaceutical substance based on polysaccharides from birch leaves.

Isolation and Characterization of Water-Soluble Chromoproteins from Arthrospira platensis Cyanobacteria: C-Phycocyanin, Allophycocyanin, and Carotenoid- and Chlorophyll-Binding Proteins

A method using chromatography on DEAE-Toyopearl 650M was developed for the simultaneous extraction of water-soluble chromoproteins from Arthrospira platensis cyanobacteria cells. These chromoproteins were C-phycocyanin, allophycocyanin, and carotenoid- and chlorophyll-binding proteins. The purity of the isolated C-phycocyanin was 4.42 (A620/A280). The allophycocyanin purity was 3.40 (A652/A280). The phycocyanin purity was confirmed by the presence of only two bands obtained during SDS-PAGE: α-subunit (17 kDa) and β-subunit (18 kDa). The isolated carotenoid- and chlorophyll-binding proteins were analyzed by high-performance exclusion chromatography on TSK-GEL 2000SW (XL) with detection at three wavelengths (280, 480, and 678 nm). The spectral, chromatographic, and electrophoretic analyses of chromoproteins, as well as pigment analysis, made it possible to conclude that the carotenoid—chlorophyll a binding protein was a xanthophyll-chlorophyll a protein complex, and the chlorophyll a binding protein was a chlorophyll a protein complex. The molecular weight of the proteins was determined by high-performance exclusion chromatography and SDS-PAGE to be 57 and 16 kDa, respectively. The photoprotective properties of these proteins and their possible functioning as part of evolutionary precursors of photosynthetic systems are discussed.

Size exclusion and reversed-phase high-performance liquid chromatography/UV for routine control of thermal processing of cows' and donkey milk major proteins

Cows' and donkey milks (raw and thermally processed) and respective whey were analysed for quantification of major proteins. Two different chromatographic approaches, size exclusion (SE-HPLC) and reversed-phase high performance liquid chromatography (RP-HPLC) both coupled to UV detection were used. Usefulness of these methods for routine control of the effect of thermal processing was evaluated. The external standard method was used to calibrate the SE-HPLC and RP-HPLC systems. Concerning quantification of β-lactoglobulin (β-lg), α-lactalbumin (α-la), lysozyme (lys), and total casein (cn), no significant differences between results obtained by SE-HPLC and by RP-HPLC (t-test, P>0·05) were observed for raw milks and whey. Heating of cows' milk promoted aggregation of denatured proteins as observed by SE-HPLC, whereas α-la and β-lg from donkey milk were stable to thermal processing at 100 °C (5 min). Lys was quantified in donkey raw milk and whey however, in thermally processed donkey milk lys was denatured and could not be quantified by HPLC.

The effect exerted by composition and temperature on the decomposition stability of anosovite solid solutions

Chemical modification of potato carboxy starch in the sodium pyrosulfate—dimethyl sulfoxide system was studied with the aim of preparing water-soluble highly substituted sulfo esters. The dependence of the degree of sulfo group substitution on the reaction conditions was studied in detail. The optimal conditions ensuring formation of water-soluble sulfo esters of carboxy starch with the maximal sulfur content were determined. The carboxy starch sulfo ester samples synthesized were characterized by elemental analysis, IR and 13C NMR spectroscopy, and high-performance exclusion chromatography.

Sulfation of carboxy starch with sodium pyrosulfate in dimethyl sulfoxide

Chemical modification of potato carboxy starch in the sodium pyrosulfate— dimethyl sulfoxide system was studied with the aim of preparing water-soluble highly substituted sulfo esters. The dependence of the degree of sulfo group substitution on the reaction conditions was studied in detail. The optimal conditions ensuring formation of water-soluble sulfo esters of carboxy starch with the maximal sulfur content were determined. The carboxy starch sulfo ester samples synthesized were characterized by elemental analysis, IR and 13C NMR spectroscopy, and high-performance exclusion chromatography.

Use of high-performance exclusion chromatography for analysis of the molecular mass of polysaccharides produced from buckwheat and sunflower wastes

High-performance exclusion chromatography was used to study polysaccharide samples obtained by successive extraction with water, ammonium oxalate, and alkali from waste produced in buckwheat and sunflower processing. The molecular-mass distribution of fractions (protein-polysaccharide complex, polysaccharides, and low-molecular-weight compounds) was analyzed in relation to sources of carbohydrates and methods of their production.

Application of High-Performance Exclusion Chromatography to Studying and Monitoring the Process of the Preparation of Agar

A procedure was proposed for the chromatographic analysis of mixtures of proteins and polysaccharides by high-performance exclusion chromatography on Shodex Asahipak GS-520H and GS-620H series-coupled columns with elution with water and refractometric and UV (280 nm) detection. The procedure substantially simplifies sample preparation. It was used for studying the solvent extraction of agar from the red alga Ahnfeltia tobuchiensis.

Aplicação da cromatografia por exclusão e da cromatografia gasosa de alta resolução na análise do café

The combination of high performance exclusion chromatography (HPEC) and gas chromatography (GC) was applied to the analysis of six coffee samples that were previously characterized by sensory tests as of good or poor quality. The data obtained by the two techniques were statistically evaluated by Principal Components Analysis (PCA) using selected peak areas. The results showed the potential of the described techniques for coffee analysis. The HPEC technique monitored with the U.V. detector at 272 nm and followed by PCA may be correlated with sensorial data, particularly if a wider group of samples is used.

Physical Characterization of Heparin by Light Scattering

Dynamic and electrophoretic light scattering were used to measure the size and charge heterogeneity of a commercial preparation of heparin. For this preparation of porcine mucosal heparin (Mr = 10–20 kDa), the diffusion coefficient was 1.2 ± 0.5×10−8cm2/s and the mobility was 4.4 ± 0.9×10−4cm2/V s for an unfiltered solution at 22°C in distilled water. This diffusion constant is 2 orders of magnitude smaller than expected for a molecule the size of heparin. A fast diffusion component of 5.8 ± 1.0×10−7cm2/s, corresponding to the individual molecule, was observed in the presence of 2M NaCl, where single molecule motion is better observed. This indicates that a portion of the heparin population is in an aggregated state, which produces a higher scattering intensity than individual heparin molecules. The weight percentage of the aggregates was 5–10 as measured by high performance exclusion chromatography. These aggregates were stable up to a temperature of 75°C as measured by light scattering. This suggests that the aggregates are made up of tightly bound heparin molecules. From the diffusion coefficients we estimate the average aggregate to be made up of about 50 heparin monomers, and from the mobility, we estimate the electrophoretic charge on the aggregate to be about 1000 or about 20 electrophoretic charges for each heparin monomer. The electrophoretic light‐scattering measurements also indicate that the aggregate scattering species have very similar surface charge densities resulting from the aggregates being formed from heparin molecules. These results can provide a framework to interpret future light‐scattering data for various preparations of heparin.

Production and characterization of Rhizobium meliloti M5N1 water soluble exopolysaccharides using high performance liquid chromatography.

In this paper, we propose a rapid measurement of both exopolysaccharide and residual fructose by high performance exclusion chromatography with the contribution of several detectors. This method has been used with exopolysaccharide from Rhizobium meliloti M5N1 strain cultivated on RC medium (7) with fructose as a carbon source

Determination of acetylated caffeine metabolites by high-performance exclusion chromatography

Determination of acetylated caffeine metabolites by high-performance exclusion chromatography

Application of high performance exclusion chromatography for the characterization of dextran preparations

Application of high performance exclusion chromatography for the characterization of dextran preparations

The multi-residue determination of coumarin-based anti-coagulant rodenticides in animal materials by high-performance liquid chromatography

The rodenticides brodivacoum, difenacoum, coumatetralyl and warfarin are determined in animal relicta by high-performance exclusion chromatography on porous silica. The first three compounds are not separated, but are subsequently differentiated by adsorption or reversed-phase high-performance liquid chromatography of the appropriate eluate fraction collected from the exclusion column. The method is rapid, and clean-up (on Sep-Pak silica cartridged) is simple. Mean recoveries from spiked substrates were generally above 80% at levels of 0.1–1.0 mg/kg. Routine limits of determination are about 0.05–0.1 mg/kg for warfarin and about 0.02 mg/kg for the other compounds. If analysis for warfarin is not required, the latter limit can be lowered to about 1 μg/kg by a slight modification to the clean-up step.

Determination of the molecular weight distribution of polymers by high performance exclusion chromatography on microcolumns packed with lichrospher silica gel; linear calibration plot

Journal of High Resolution ChromatographyVolume 4, Issue 8 p. 425-426 Short Communication Determination of the molecular weight distribution of polymers by high performance exclusion chromatography on microcolumns packed with lichrospher silica gel; linear calibration plot J. J. Kever, J. J. Kever Institute of Macromolecular Compounds of the Academy of Sciences of the USSR, Leningrad, USSRSearch for more papers by this authorB. G. Belenkii, B. G. Belenkii Institute of Macromolecular Compounds of the Academy of Sciences of the USSR, Leningrad, USSRSearch for more papers by this authorE. S. Gankina, E. S. Gankina Institute of Macromolecular Compounds of the Academy of Sciences of the USSR, Leningrad, USSRSearch for more papers by this authorL. Z. Vilenchik, L. Z. Vilenchik Institute of Macromolecular Compounds of the Academy of Sciences of the USSR, Leningrad, USSRSearch for more papers by this authorO. I. Kurenbin, O. I. Kurenbin Institute of Macromolecular Compounds of the Academy of Sciences of the USSR, Leningrad, USSRSearch for more papers by this authorT. P. Zhmakina, T. P. Zhmakina Institute of Macromolecular Compounds of the Academy of Sciences of the USSR, Leningrad, USSRSearch for more papers by this author J. J. Kever, J. J. Kever Institute of Macromolecular Compounds of the Academy of Sciences of the USSR, Leningrad, USSRSearch for more papers by this authorB. G. Belenkii, B. G. Belenkii Institute of Macromolecular Compounds of the Academy of Sciences of the USSR, Leningrad, USSRSearch for more papers by this authorE. S. Gankina, E. S. Gankina Institute of Macromolecular Compounds of the Academy of Sciences of the USSR, Leningrad, USSRSearch for more papers by this authorL. Z. Vilenchik, L. Z. Vilenchik Institute of Macromolecular Compounds of the Academy of Sciences of the USSR, Leningrad, USSRSearch for more papers by this authorO. I. Kurenbin, O. I. Kurenbin Institute of Macromolecular Compounds of the Academy of Sciences of the USSR, Leningrad, USSRSearch for more papers by this authorT. P. Zhmakina, T. P. Zhmakina Institute of Macromolecular Compounds of the Academy of Sciences of the USSR, Leningrad, USSRSearch for more papers by this author First published: August 1981 https://doi.org/10.1002/jhrc.1240040817Citations: 5AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume4, Issue8August 1981Pages 425-426 RelatedInformation

High-performance exclusion chromatography of water- soluble polymers with chemically bonded stationary phases

Chemically bonded stationary phases with 14 different functional groups have been evaluated for use in the exclusion chromatography of water-soluble polymers. They were characterized by their interaction with different polyethylene glycol standards. A bonded glycinamide and a diamine phase showed no interaction with polyethylene glycols and such phases bonded to silicas having different pore diameter distribution are suitable for exclusion chromatography. A bonded amide phase proved to be more suitable for exclusion chromatography of polyvinyl pyrrollidones, dextrams and gelatine but partially retained the polyethylene glycols. For the separation of polymers in the molecular-weight range 100–70,000 the average pore diameter of the silica matrix should be at least 200 Å; for those in the molecular-weight range 80,000–500,000 the pore diameter should be ca. 500 Å.

Band dispersion in high-performance exclusion chromatography

The dispersion of polymer samples eluted in the exclusion mode from columns of Hypersil and SG60F (a highly porous silica gel) has been measured for a range of polymer standards over a range of elution velocities and from columns of different lengths. From experiments with columns of different lengths operated at the same velocity, the polydispersities of the polymer standards were obtained and ranged from 1.007 to 1.052. From experiments at different linear velocities, mass transfer coefficients were obtained from which the ratio of the diffusion rates of polymers in bulk eluent to the diffusion rates within the silica gel matrix could be found. For Hypersil these ranged from ca. 6 for PS2K and PS4K (MW 2000 and 4000 respectively) to ca. 17 for PS33K (MW 33,000) indicating fairly severe restrictions to diffusion within the pores of the matrix especially for nearly excluded materials. Measurements with a pure oligomer of polystyrene (MW ≈ 3000) confirmed the validity of the above method of separating spreading effects of polydispersity and kinetics and gave a reduced plate height—velocity curve overlapping that for benzene. Measurements of spreading of excluded polymer samples indicated anomalous behaviour at low flow-rates and with long columns. Measurements of the loading capacity in exclusion chromatography showed that samples should not exceed ca. 1 μg per cm 3 of column packing if overloading is to be avoided. It is concluded that the dispersion of bands of polymers eluted in the exclusion mode from silica gels obeys the same kinetic relationships as the dispersion of bands in retentive chromatography. The study confirms, however, that the major contributor to the dispersion of polymer samples eluted in the exclusion mode is their polydispersity.

High-performance exclusion chromatography of low-molecular-weight additives

The use of high-performance exclusion chromatography with small pore-size gels of 8–10-μm particle diameter for the analyses and/or clean-up of a variety of sample types was investigated. In many cases, low molecular weight additives from polymers or oils could be determined directly since the latter were of a sufficiently higher molecular weigh to be resolved. In those cases where the additives were unseparated, the exclusion technique served as a clean-up method and these compounds could be further by another liquid chromatographic mode, such as reversed phase. The technique was applied to a steroid in a cream base, polyethylene additives, sulfur in a compounded rubber and a pesticide formulation, DDT in butter and additives in vegetable and lubricating oils.

Chemically bonded stationary phases for aqueous high-performance exclusion chromatography

The preparation of chemically bonded stationary phases based on a silica support for aqueous exclusion chromatography is discussed. A defined amount of functional groups can be bonded on to the silica surface only if the appropriate silane is prepared prior to binding it to the surface. The properties of the prepared stationary phases, i.e., wettability by water, adsorption of water-soluble polymers, etc., are described. Stationary phases with amide bonds can be used to separate by exclusion chromatography polystyrenes and polyethylene glycols in dimethylformamide as eluent as well as polyethylene glycols and dextrans in water as eluent. The graphs of molecular weight versus elution volume are, with acceptable deviations, independent of the nature of the polymer.