High-Performance Size Exclusion Chromatography HPSEC

2 High-Performance Size Exclusion Chromatography (HPSEC) 

In the following subsection, HPSEC on polystyrene gels using THF as solvent is emphasized since this system has been found to give the most reliable 

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A. Development of Silica Particles for High-Performance Size Exclusion Chromatography (HPSEC)... 

Modern SEC columns are packed with material other than polystyrene gels, such as porous silica particles or highly cross-linked styrene-divinylbenzene copolymers. Because of improvements in speed and resolution, the term SEC is sometimes replaced by the term high-performance size-exclusion chromatography (HPSEC). 

Analysis of the MHR by high-performance size-exclusion chromatography (HPSEC) revealed three distinct populations to be present, which were isolated on a preparative scale. The composition of the populations differed mainly in the relative proportion of rhamnose, xylose and the amount of methyl esters and acetyl groups, although the general characteristics were rather similar (Table 2). However, degradation studies with RGase showed that, in contrast... 

Molecular weight distributions were examined by high performance size-exclusion chromatography (HPSEC) as described [22] on two serial Shodex OHpak KB-803 and KB-805 columns (0.8 x 30 cm Showa Denko, Japan) with a OHpak KB-800P guard column (0.6 x 5 cm), equilibrated at 1 mL/min in 0.1 M UNO3. The system was calibrated with a pullulan calibration kit (Showa Denko). 

Ysambertt, F., Cabrera, W., Marquez, N., Salager, J.L. (1995). Analysis of ethoxylated nonylphenol surfactants by high performance size exclusion chromatography (HPSEC). J. Liq. Chromatogr. 18(6), 1157-1171. 

High Performance Size Exclusion Chromatography (HPSEC) A Varian Model 5000 liquid chromatograph equipped with a variable wavelength UV detector, two columns in series (PL gel, 300 x7.5 mm, particle size 5/im, porosity of 50 and 500A), was used, THF being the eluent. 

High-performance size exclusion chromatography (HPSEC) techniques with multiple online detectors (e.g., UV-, fluorescence-, or element-specific systems, Figure 10.6) enables a better understanding of quantitative and qualitative DOM properties... 

High-performance size-exclusion chromatography (HPSEC) was used for competition studies. Solubilized HLA-DR1 (0.13 pM) was incubated for 48 h at 37 °C with the N-ter-minally 7-amino-4-methylcoumarin-3-acetic acid (AMCA)-labeled IM-(19-31)-peptide dissolved in 150 mM sodium phosphate, pH 5.5, containing 15 % (v/v) acetonitrile, 0.1 % (w/v) Zwittergent-12 (Calbiochem) and a cocktail of protease inhibitors (0.2 mM PMSF, 5 pM leupeptin, 10 pM pepstatin, and 1 pM chymostatin). Competition assays were performed in a 1.5 pM solution of AMCA-peptide as competitors, different peptides, the peptide library or peptide sublibraries were added in concentrations ranging from... 

High-performance size-exclusion chromatography (HPSEC) or conventional SEC may help to determine fragmentation or aggregation, depending on the different sizes. Clipped chains may also be separated from the intact compound... 

E-1000 and E-linear p Bondagel high performance size exclusion chromatography (HPSEC) columns were calibrated in root-... 

Alberts, J. J., Takacs, M., and Egeberg, P. K., Total luminescence spectral characteristics of natural organic matter (NOM) size fractions as defined by ultrafiltration and high performance size exclusion chromatography (HPSEC), Org. Geochem., 33, 817-828, 2002. 

Carvalho et al. [108] studied chain degradation in TPS conqtosites of maize starch plasticized with glycerol and reinforced with wood pulp. The product was characterized by high performance size-exclusion chromatography (HPSEC). The matrix (starch/glycerol) and the composites were prepared in an intensive batch mixer at 150-160°C, with glycerol and fibre contents in the range of 30-50 per cent and 5-15 per cent, respectively. The HPSEC curves obtained for different levels of plasticization without fibre are shown in Fig. 15.5. 

Figure 15.5 High performance size-exclusion chromatography (HPSEC) of native com starch, and TPS with 20 per cent (Gli-20), 30 per cent (Gli-30) and 40 per cent glycerol (Gli-40). Reproduced with permission from Reference [108],...

A typical profile from a high-performance size exclusion chromatography (HPSEC) column is shown in Fig. 2. With ideal SEC systems, plots of the log of molecular weight against Kq produce calibration curves like those shown in Fig. 3. SEC supports of a single pore size with a narrow pore distribution should produce curves that are linear over a wide range of Kq values, usually 0.1-0.8. In order to achieve a linear calibration curve, it is essential that there be no Interaction between the column support material and the solute. Because solute-support interactions have been observed in every support material that has ever been introduced for SEC, the nature and characterization of these retentive phenomena will be discussed in detail later in the chapter. 

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