Direct Determination of Molecular Weight Distribution by Size Exclusion Chromatography with 750 MHz 1H NMR Detection (On-Line SEC-NMR)
نویسندگان
چکیده
منابع مشابه
Determination of molecular weight of heparin by size exclusion chromatography with universal calibration.
The molecular weight (MW) of heparin can be accurately determined by size exclusion chromatography using "universal calibration." A universal calibration curve was constructed for Superose 12 with standard pullulan samples and verified using characterized ficoll fractions. This calibration yielded the correct MW of heparin as determined by light scattering, when the ionic strength of the mobile...
متن کاملDetermination of the molecular weight of low-molecular-weight heparins by using high-pressure size exclusion chromatography on line with a triple detector array and conventional methods.
The evaluation of weight average molecular weight (Mw) and molecular weight distribution represents one of the most controversial aspects concerning the characterization of low molecular weight heparins (LMWHs). As the most commonly used method for the measurement of such parameters is high performance size exclusion chromatography (HP-SEC), the soundness of results mainly depends on the approp...
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High performance size exclusion chromatography (HPSEC) with ultraviolet absorbance (UVA) detection has been widely utilized to estimate the molecular weight (MW) and MW distribution of natural organic matter (NOM). However, the estimation of MW with UVA detection is inherently inaccurate because UVA at 254 nm only detects limited components (mostly pi bonded molecules) of NOM, and the molar abs...
متن کاملSize-exclusion chromatographic NMR of polymer mixtures.
The use of chromatographic stationary phases or solvent modifiers to modulate diffusion properties in NMR experiments is now well established. Their use can be to improve resolution in the diffusion domain or to provide an insight into analyte-modifier interactions and, hence, the chromatography process. Here, we extend previous work using size-exclusion chromatographic stationary phases to the...
متن کاملSize-exclusion chromatography (SEC) of branched polymers and polysaccharides
Branched polymers are among the most important polymers, ranging from polyolefins to polysaccharides. Branching plays a key role in the chain dynamics. It is thus very important for application properties such as mechanical and adhesive properties and digestibility. It also plays a key role in viscous properties, and thus in the mechanism of the separation of these polymers in size-exclusion ch...
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ژورنال
عنوان ژورنال: Polymer Journal
سال: 1998
ISSN: 0032-3896,1349-0540
DOI: 10.1295/polymj.30.439