Shodex

With large companies such as Waters Corp., TOSOH Corp., Polymer Laboratories Ltd., Shodex Corp., and Phenomenex Inc. and smaller companies such as American Polymer Standards Corp., Polymer Standards Service, and Jordi Associates, all manufacturing ST-DVB GPC/SEC gel, the market has become saturated with analogous columns. All the manufacturers just men-... 

Shodex Group, Showa Denko K.K. 13-9, Minato-ku, Tokyo 105-8518, Japan... 

Showa Denko K.K. started the Shodex HPLC business in 1973 by developing columns to determine the molecular weight distributions of polymers produced at its petrochemical plant. Since then, more than 600 items of columns have been developed to achieve various kinds of analyses. Among them are several series of columns that can be used for size exclusion chromatography. The abundant variety of columns is one of the important characteristics of Shodex. Any kind of analytical requirements can be satisfied by choosing the appropriate column supplied by Showa Denko. 

Four series of Shodex columns are suited for size exclusion chromatography. 

Shodex has a wide variety of columns for organic GPC using organic solvents. The columns are packed with porous styrene-divinylbenzene copolymer gels especially developed for GPC use. Five types of standard-size GPC columns packed with different solvents are available. Downsized GPC columns are also available. 

FIGURE 6.1 Calibration curves of Shodex GPC KF-BOO series. Column Shodex GPC KF-800 series 8 mm i.d. X 300 mm. Eluent THF. Sample Polystyrene standards. 

Shodex AT-800, HT-800, and UT-800 series are designed for use at high temperature of up to 140, 140, and 210°C, respectively. These columns are suited for the analysis of polymers such as polyolefins, which are insoluble at room temperature. The UT-800 series is recommended if the sample contains ultrahigh molecular weight components (Table 6.3). 

FIGURE 6.4 Comparison of Shodex GPC UT column and conventional-type column. Column Left Shodex GPC UT-806M X 2, 8 mm i.d. X 300 mm X 2. Right Conventional type column X 2, 7.8 mm i.d. X 300 mm x 2. Eluent 0.1% BHT in ODCB. Flow rate 1.0 mL/min. Detector Rl, MALLS (multi-angle laser light scattering detector). Column temp. I45°C. Sample High-density polyethylene. 

The Shodex GPC HFIP series is packed with a hexafluoroisopropanol (HFIP) solvent. Engineered plastics, such as polyamides (nylon) and polyethylene terephthalate, were analyzed previously at a high temperature of about 140°C. Using FIFIP as an eluent, such engineered plastics can be analyzed at ordinary temperatures (Table 6.4). 

The Shodex GPC KF-600 series is packed with 3- im styrene-divinylbenzene copolymer gels in a column having a volume of about one-third compared to standard-types of columns, which are best suited for reducing the organie solvents eonsumption, shortening the analysis time, and lowering the detection limit (Table 6.5). 

TABLE 6.6 Specifications of Shodex GPC KF-800D and K-800D Columns... 

FIGURE 6.9 Epoxy resin. Column Shodex GPC KF-803L x 2, 8 mm i.d. x 300 mm x 2. Eluent THE. Flow rate 1.0 mUmin. Detector Shodex UV (2S4 nm). Column temp. Ambient. Sample 100 /xL each, Epikote 1004, Epikote 1001. 

HFIP. -----, S mM CFsCOONa/HFIP. Flow rate 1.0 mL/min. Detector Shodex Rl. Column... 

IV. Shodex OHpak SB-800HQ SERIES A. Column Characteristics... 

The packed columns of Shodex OHpak SB-800HQ series are packed with polyhydroxymethacrylate gels and are designed for use with high-resolution, high-speed aqueous size exclusion chromatography. The packed columns are best suited for the analysis of water-soluble polymers and proteins (Table 6.8). 

The Shodex OHpak SB-800 HQ series is usually not the best choice for the analysis of proteins. However, in some cases, such as when an alkaline... 

TABLE 6.9 Usable Organic Solvent for Shodex OHpak SB-800 HQ Series... 

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