Conventional silica based HPLC stationary phases are usually bonded with mono-type alkyl chain molecules, e.g., C18, C8, etc. Recent studies have revealed that synergistic effects can be obtained when the bonded surface consists of C18 mixed with a shorter chain such as C8, amide or nitro-phenyl, etc. These new products offer different selectivity, coordinating multi-functionality, as well as a spacer effect (C18/C8).
It is difficult to produce a uniformly bonded C18 surface on silica due to steric hindrance of the bulky C18 chain. This
problem can be easily overcame when the surface is bonded with mixed chain lengths, C18 and a shorter silane. As a result, there are many advantages: improved surface uniformity, better penetration of molecules during partitioning due to less steric hindrance, and different selectivity compared to a mono-chain type stationary phase.
As one of the leaders in separation technologies, Bonna-Agela Technologies has innovatively developed a family of nonionic, mixed-phase HPLC/SFC columns.
Improved performance from a mixed-phase C18/C8 (1:1) column compared to mono-chain C18 or C8 columns
Pore Size:100 Å; Available Particle Size: 5 μm; pH=1.5-9.0; pH range of 2.0-6.0 is recommended for better lifetime.
● Alternative selectivity;
● Improved selectivity for stereo isomers, better differentiation of molecular shapes;
● Better peak shape due to uniformity of the bonding;
● Balanced hydrophilicity and hydrophobicity: extended retention for polar compounds; non-excessive retention for
strong hydrophobic compounds.