HPLC Column
User's Manual
DD stands for Double Durability. In general, the durability of stationary phase decreases as its alkyl group length becomes short. Osaka Soda developed a C8 phase featuring both acidic resistance and basic resistance by applying a special polymer coating technology.
Hydrophobicity and surface polarity parameters of Osaka Soda columns
Exceptional acidic and basic resistance
C8 phases have been considered useful in analyzing substances quickly. However, having a shorter alkyl chains than C18 ones, they used to show a limited durability. Hydrophobic alkyl groups play important roles not only in chromatographic separation but also in the protection silica surface and binding structure against various chemical attacks by mobile phases. Osaka Soda found a way to establish a chemically stable C8 phase by applying the unique polymer coating technology.
· pH range of use
pH 1.5 to 10
· Excellent durability
Excellent acidic resistance
A life time of a column under acidic conditions largely depends on the content of organic solvent in the mobile phase. The durability test used here was under pH1 and no organic solvent, which is considered extremely tough.
Excellent basic resistance
All the C18 phases use silica as a chromatographic support. Silica is known to dissolve in neutral to basic conditions. The durability test was designed to be tough, being carried out under pH 10, a highly basic condition.
Fig. 1
· Low pressure
The column pressure was compared in a mobile phase of 50% methanol. Since the 50% methanol maximizes the viscosity, the column pressure also becomes the highest.
Fig. 2
· Excellent peak shapes of basic compounds
The CAPCELL PAK Series provides columns made of silica coated with silicone polymer that are not affected by residual silanol groups or metallic impurities. Therefore, extremely symmetrical peak shapes free of tailing are achieved even from a pyridine, a basic compound used for evaluating interaction with residual silanol groups.
Fig. 3 Fig. 4
· Optimum for quick analysis of various hydrophobic mixtures
· Rapid, sharp elution of very hydrophobic compounds, yet keeping retention of polar compounds
Fig. 5
· USP category L7
· Also available worldwide
Property values
Pore size
Particle size
Specific surface area
C% Density
Functional group Acceptable pH USP
8 3 300 11 3.8 Octyl group 1.5~10 L7
8 5 300 11 3.8 Octyl group 1.5~10 L7
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