"Without this lot quality control checks for the product would have not possible." Branched co-polymers are no problem great for pH." Mary Baker, MCPS The combined information from the MALS and the viscometry detector can't be beaten. "I have been using MALS since the 1980's - Wyatt's have always been the best value. "Most versitile SEC detector on the market - great product." MicroOptilab™ - The first RI detector specifically designed for use with all UHPLC systems. The high-concentration option accommodates protein concentration up to 180 mg/mL. Optilab ® - A unique on-line differential refractometer for measuring concentration of any macromolecule, regardless of chromophores. MicroViscoStar ® - Similar to the ViscoStar but designed specifically for use with UHPLC/APC. Its ease-of-use and serviceability make it the perfect companion for Wyatt's DAWN ® light scattering and Optilab ® refractive index detectors. The ViscoStar incorporates multiple novel technologies to provide the highest sensitivity, stability and solvent compatibility of any available viscometer for GPC. ViscoStar ® - A highly sensitive, on-line differential viscometer used in conjunction with SEC-MALS to determine the size and conformation of all types of biopolymers, synthetic polymers and even proteins and peptides. Combination of SEC/MALS experimental procedures and theoretical analysis for studying the solution properties of macromolecules. Influence of chain architecture on the mechanochemical degradation of macromolecules. Depletion interactions: effects of added homopolymer on ordered phases formed by spherical block copolymer micelles. Importance of multi-angle light scattering in polyolefin characterization. Detection orthogonality in macromolecular separations: role of the on‑Line viscometer in characterizing polymers at conditions of “spectroscopic invisibility”. Measurement of Mark-Houwink coefficients ab initio.Absolute determination of molar mass and size regardless of conformation.The ASTRA ® software not only analyzes polymers based on the Mark-Houwink equation and Universal Calibration technique but, with a MALS detector, can even calculate Mark-Houwink coefficients.īut these instruments can do much more! By simply adding a DAWN, transform a basic SEC-IV setup into a powerful SEC-MALS-IV polymer characterization station, to analyze from first principles: The ViscoStar ® differential viscometer coupled with an Optilab ® differential refractometer to any GPC system provides superior measurements of intrinsic viscosity for characterization of all types of polymers. While a fluorescence blocking filter may be incorporated into the DAWN ®, this does not always provide a sufficient solution to strongly fluorescing polymers. When the polymers fluoresce under excitation by the MALS laser, the fluorescence greatly increases the apparent scattering signal producing erroneous molecular weights.When the solvent and solute have the same refractive indices (making dn/dc=0), the polymer does not scatter light.Though these techniques are less rigorous than MALS, SEC-IV may be the optimal means of characterizing materials not amenable to SEC-MALS analysis: The two primary methods are Mark-Houwink analysis (using empirical values of Mark-Houwink coefficients from the literature) and Universal Calibration, which is appropriate for all linear, random coil polymers. Intrinsic viscosity in conjunction with size exclusion chromatography (SEC-IV) has long been used by the polymer community to characterize molar mass. Dynamic & Electrophoretic Light Scattering.
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