Specma Reversed Phase columns for HPLC and UHPLC Most often used stationary phase in reversed phase mode. Silica gel-based columns with C18 modification are available with or without end capping. Classically end capped phases are slightly more hydrophobic and unpolar than the not end capped phases.
C18 columns are ideally used for acidic, basic and neutral analytes in reversed phase mode, e.g.
Specma C18 AQ/A columns (HYDROPHILIC / AQUEOUS C18) for polar reversed phase applications with 100 % aqueous mobile phase
C18 stationary phase for the analysis of more polar and hydrophilic compounds in reversed phase mode (USP L1). Silica gel-based columns with C18 modification with hydrophilic end capping. Because of their modification, C18A or C18 AQ phases can be operated under 100 % aqueous conditions without destroying the stationary phase, what is not recommended for classical C18 phases caused by their hydrophobicity.
These phases are ideal for the analysis of:
Columns for more unpolar analytes in Reversed Phase
Specma C18 stationary phase with a special, high efficiency or polymeric unpolar end capping style. Because of the high carbon content and the protection of the Silica gel these materials are also suited for the use of mobile phase in an extended pH range from typically pH 1-12.
While a high end capped C18 phase is characterized mostly by the high carbon content, a polymeric end capped phase also provides an increased steric selectivity
Hydrophobic and polar characteristics combined
Specma C18 stationary phase for the analysis of more polar and hydrophilic compounds in reversed phase mode. Silica gel-based columns with C18 modification with hydrophilic end capping.
These phases are ideal for the analysis of:
For the separation of these compounds these supports exhibit an enhanced polar selectivity. That means: In comparison to a classical bonded C18 column, acidic compounds show a higher retention whereas basic compounds show a slight decrease of retention on an embedded polar column.
Specma C8 columns for HPLC and UHPLC
Specma C8 is a silica gel based stationary phase in reversed phase mode with alternative selectivity compared to C18 phases. C8 modifications are available with a slightly hydrophobic end capping or without end capping.
Compared to C18 phases, these columns show less retention due to the lower hydrophobicity.
These phases are ideal for the analysis of:
Specma C8 AQ columns for highly polar reversed phase applications with 100 % aqueous mobile phase
Hydrophilic C8-AQ phase with alternative, more polar selectivity, suited for the use with pure aqueous mobile phases Alternative selectivity to C8 with stronger interactions for polar compounds; 100% aqueous applications with very polar compounds.
Columns for more unpolar analytes in Reversed Phase
The Specma C8 QZ stationary phase in Reversed Phase mode has alternative selectivity compared to C18-QZ phases. The silica gel based columns feature a C8- QZ modification with full hydrophobic endcapping and base deactivation, making them stable over a wider pH range.
Hydrophobic and polar characteristics combined in C8-TQ columns with polar embedded group
Specma C8 TQ stationary phase for the analysis of more polar and hydrophilic compounds in reversed phase mode. Silica gel based columns with C8 modification with hydrophilic endcapping.
These phases are ideal for the analysis of:
pharmaceuticals, where analytes often have basic or acidic groups. For the separation of these compounds these supports exhibit an enhanced polar selectivity. That means: In comparison to a classical bonded C8 column acidic compounds show a higher retention whereas basic compounds show a slight decrease of retention on an embedded polar column
Specma Cyano or CN for Normal Phase and Reversed Phase
CN is one of the most versatile stationary phases that can be used in reversed phase mode as well as in normal phase mode.
The cyano modification supports the pi-pi interaction as well as polar and hydrophobic interactions with low polarity solvents. These phases are preferred for compounds with double bonds and aromatic groups. Cyano bonded phases show unique selectivity for polar compounds and are more suitable than bare silica for normal-phase gradient separations. The cyano functional group is a strong dipole that can interact with other dipoles or induce dipoles on solutes. These phases also exhibit moderate hydrophobicity due to the alkyl linker
Due to the quick equilibration time of the CN bonded phase, it is the best choice for gradient elution in normal phase mode. CN phases can be used as a less polar alternative to Si phases.
The material is typically preferred for
Specma C1 columns for reversed phase applications
C1 stationary phases show the lowest retention of all reversed phase phases on the
market. The application area is mainly the separation of nonpolar solutes. It can also
be used for the separation of proteins in the HIC mode.
The C1 phases from SPECMA are available without endcapping
Specma C4 columns for Reversed Phase in HPLC and UHPLC
C4 stationary phases (USP L26) are often used in reversed phase mode for different application areas. They are suitable for:
SPECMA offers C4 phases with a classical slightly hydrophobic end capping or without end capping.
Specma C30 for Reversed Phase applications
C30 is a stationary phase with a high carbon load. The high coverage of the support
results in a very dense packing and in an excellent shape selectivity and stability
even at pH 1. The C30-bonding type is available with several pore sizes and in
several particle sizes. Especially the wide pore supports are showing enhanced
shape selectivity.
The application field of the C30 packings is the separation of isomers of
Carotenoides and other long alkyl chain solutes, that cannot be separated on
classical C18 columns.
Specma Phenyl columns for Reversed Phase in HPLC and UHPLC
Phenyl stationary phases (USP L11) in reversed phase mode with alternative selectivity for
The polarity is similar to C8 modification but with different selectivity for polar aromatics, polycyclic aromatic hydrocarbons, fatty acids etc. Phenyl phases with a classical slightly hydrophobic end capping or without end capping.