Jordi Labs has recently developed a novel packing material for GPC systems. This column packing is based on 100% divinylbenzene providing enhanced mechanical stability and utilizes a new synthetic process which results in a monodisperse polymer column packing. It is well known that broad particle size distributions in particle based columns produces variations in packing density, lowers column resolution, reduces the column permeability and generates high back pressure. New generation Jordi GPC columns prepared with monodisperse 100% divinylbenzene particles with precisely controlled particle diameter and finely controlled pore structure provide high efficiency, high separation capacity and low back pressure with greater bed stability. Scanning electron micrographs and particle size distribution of 5 μm macroporous column packing material with 103 A pore sizes are shown in Figure 1. The uniform size distribution and perfect spherical shapes are clearly seen.
To maximize GPC resolution, the key is to use a column containing the maximum number of pores of the desired size to separate the molecular weight range of interest. New generation individual pore size Jordi Resolve columns 5 μm (7.8 mm ID x 300 mm L) provide high resolution in the specific molecular weight ranges given in Table 1.
The linear part of each calibration curve defines the molecular weight range of each individual porosity column. To cover a wider range of molecular weight with a constant resolution for the analysis of polydisperse or unknown materials, Jordi Labs designed the mixed bed Resolve column 5 μm (7.8 mm ID x 300 mm L). Mixed bed Resolve columns allows separation over the molecular weight range from 200 to 3,000,000 g/mol (PS equivalent) with a coefficient of determination (R2) of 0.999, as shown in Figure 2, and an industry leading specification of 70,000 theoretical plates. In addition, the high pore volume of Jordi Resolve columns provides increased resolution compared to the competitive columns of the same particle size and length. Accurate blending of individual pore sizes provides a wide molecular weight range and smooth peak shapes.
For higher molecular weights, Jordi Labs offers its Jordi Resolve DVB 13 μm columns. New generation Jordi Resolve columns (7.8 mm x 300 mm) are produced to allow separation over the molecular weight range from 500 to 12,000,000 g/mol (PS equivalent). Polyolefins often have broad molecular weight ranges characterized by high polydispersity values. Jordi Labs has developed mixed bed columns especially for these broad distribution samples which were designed by blending a large number of individual pore size packing materials.