When Chromatography is Important
Detailed size or molar mass distribution information is useful in many areas such as investigating protein aggregation and understanding (or predicting) polymer properties. Since chromatography fractionates a sample before analysis, it is an ideal tool for characterizing these distributions.
Sometimes, calibration curves relating mass or size to elution volume can be obtained by a series of measurements of known standards. However, this column calibration is often impossible due to the unique nature of the analytes; suitable standards, which must match both analyte chemistry and structure, are simply unavailable. Fortunately, with judicious choice of detectors, column calibration is unnecessary for absolute size and absolute molecular weight determination.
Brookhaven Instruments provides detectors for determining analyte size (NanoDLS), analyte molecular weight (BI-MwA), and analyte mass distribution (BI-DNDC), and without the need for column calibration.
Determine size (hydrodynamic radius) as a function of elution volume with the NanoDLS. This extremely sensitive dynamic light scattering instrument is an excellent choice for determining the size of proteins and their aggregates in a chromatography measurement.
Determine absolute molecular weight with the BI-MwA and an appropriate concentration detector. The BI-MwA is a seven-angle, flow-through light scattering instrument designed specifically for molecular weight determination. Augment it with the BI-DNDC differential refractometer for use as an RI concentration detector.
Determine intrinsic viscosity and concentration using the BI-2020 dual detector. Ideal when universal calibration is preferred over light scattering or as another method for characterizing difficult polymer samples.
Contact the experts at Brookhaven Instruments for details about how our instruments can solve your analysis problems.