Size exclusion chromatography methods

These new technological advances also have impacted the work of the American Society for Testing and Materials (ASTM). The ASTM committee D20.70.04 currently is involved in developing new size exclusion chromatography methods (GPC) that incorporate these advances. 

K. Grob and I. Kalin, Attempt for an on-line size exclusion chromatography method for analyzing pesticide residues in foods , J. Agric. Food Chem. 39 1950-1953(1991). 

Cutler, P. (1996a) Size-exclusion chromatography, Methods Mol. Biol. 59, 269-275. 

The Soxhlet extraction method discussed in Section 6.6 can be used to separate the sol and gel fractions of a gel in the gelation regime, allowing direct determination of the gel fraction gel- Percolation theory expects the molar mass of a network strand M to be the same as the characteristic molar mass in the sol fraction. Hence, M can be determined by the size exclusion chromatography methods of Section 6.6, applied to the sol fraction. Equation (7.93) is tested in Fig. 7.19, where the shear modulus is shown to be proportional to Pgei/M. ... 

Greene, S.V. Gatto, V.J. Size-exclusion chromatography method for characterizing low molecular mass antioxidant lubricant additives. J. Chromatogr. A, 1999, 841,45-54. 

Pulse Laser Polymerization-Size Exclusion Chromatography Method of Determination 28... 

A detailed overview of experimental techniques for measurement of kc can be found in the review of Bagryanskaya and Marque. The most popular method is laser flash photolysis-kinetic absorption spectroscopy. A pulsed lamp polymerization-size exclusion chromatography method developed by Guillaneuf et allows measurement of kc for polymeric radicals. 

SI units stands for Systeme International d Unites. These are the internationally agreed on units for measurements, (p. 12) size-exclusion chromatography a separation method in which a mixture passes through a bed of porous particles, with smaller particles taking longer to pass through the bed due to their ability to move into the porous structure, (p. 206)... 

This reversed-phase chromatography method was successfully used in a production-scale system to purify recombinant insulin. The insulin purified by reversed-phase chromatography has a biological potency equal to that obtained from a conventional system employing ion-exchange and size-exclusion chromatographies (14). The reversed-phase separation was, however, followed by a size-exclusion step to remove the acetonitrile eluent from the final product (12,14). 

The molecular weight of SAN can be easily determined by either intrinsic viscosity or size-exclusion chromatography (sec). Relationships for both multipoint and single point viscosity methods are available (18,19). Two intrinsic viscosity and molecular weight relationships for azeotropic copolymers have been given (20,21) ... 

Hydroxyl number and molecular weight are normally determined by end-group analysis, by titration with acetic, phthaUc, or pyromellitic anhydride (264). Eor lower molecular weights (higher hydroxyl numbers), E- and C-nmr methods have been developed (265). Molecular weight deterrninations based on coUigative properties, eg, vapor-phase osmometry, or on molecular size, eg, size exclusion chromatography, are less useful because they do not measure the hydroxyl content. 

Stmctural and chemical modification of urethane containing polymer matri-ces with macrocycles - calixarenes having reactive hydrazide groups have been carried out and stmcture, physico chemical and sensor properties of polyure-thanesemicarbazides (PUS) synthesised have been studied. The polymers obtained (on the base of polypropylene glycol MM 1000 and polysiloxane diol MM 860, hexamethylene diisocyanate and calixarene dihydrazide) are identified by IR-spectroscopy, size exclusion chromatography (SEC), DSC, WAXS and SAXS methods. 

Size exclusion chromatography (SEC, also known as GPC and GFC) has become a very well accepted separation method since its introduction in the late-1950s by works of Porath and Flodin (1) and Moore (2). Polymers Standards Service (PSS) packings for SEC/SEC columns share this long-standing tradition as universal and stable sorbents for all types of polymer applications. In general, PSS SEC columns are filled with spherical, macroporous cross-linked, pressure-stable, and pH-resistant polymeric gels. 

ASTM D 5296 - 92 (1994). Standard Test Method for Molecular Weight Averages and Moleeular Weight Distribution of Polystyrene by High Performance Size-Exclusion Chromatography. Annual Book of ASTM Standards, Vol.08.03, pp. 419-431. 

Separation methods based on size include size exclusion chromatography, ultra-filtration, and ultracentrifugation (see Chapter Appendix). The ionic properties of peptides and proteins are determined principally by their complement of amino acid side chains. Furthermore, the ionization of these groups is pH-dependent. 

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