No more headaches!

A guide to choosing the perfect C18 column

The all-rounder in liquid chromatography: C18-columns are broadly used in pharmaceutical, food, clinical and environmental industries for reversed-phased chromatography. With thousands of options in the market, it can be overwhelming to choose the right C18 column. Shimadzu therefore offers a guide to its portfolio of C18 columns to simplify the selection process (figure 1). No more headaches through information overflow.

Shim-pack Velox: Maximize separation performance with core shell technology

Designed to maximize performance of LC systems, Shimadzu’s Shim-pack Velox columns with core shell technology enable users to achieve increased separations and faster analysis on any LC platform. Whether developing a high-efficiency LC separation method, transferring an existing method for increased throughput while maintaining resolution or trying to improve the resolution of a complex separation, Shim-pack Velox columns satisfy any users’ needs.

Due to their robustness, excellent column lifetimes are obtained, even for the most challenging sample matrices.

The Shim-pack Velox SP-C18 (Sterically Protected) series was designed specifically for applications under low pH condition, offering a well-balanced retention profile with long lifetimes even under the harsh acidic conditions needed for LC-MS(/MS) analysis.

Figure 1: Selection guide to choosing the right column. *The Velox series, with core shell technology, is the first choice for high speed analysis. The columns recommended for MS are shown in bold.

Shim-pack Scepter: excellent stability and performance under a wide range of conditions

These next generation organic silica hybrid-based columns achieve excellent stability and performance over a broad pH range. With different chemistries, Shim-pack Scepter columns are effective for method development/scouting and are suitable for a wide variety of applications. Due to their different particle sizes (1.9 µm, 3 µm, 5 µm) and different column dimensions, Shim-pack Scepter LC columns are fully scalable between UHPLC, HPLC and preparative LC, making method transfer seamless between different laboratory instrumentation.

The Shim-pack Scepter HD-C18 with its high carbon loading and therefore high hydrophobicity, is especially suited for the analysis of isomers. This is particularly useful for pharmaceutical applications where medical substances need to be separated from structurally similar impurities.

Shim-pack Arata LC columns: unprecedented resolution and peak shape of basic compounds

LC columns claiming to be desig­ned for basic compounds often fail to achieve adequate resolution of certain compounds. This problem is overcome successfully with the Shim-pack Arata columns, which solve issues such as fronting of highly polar basic compounds, peak shape deterioration of acidic compounds or long equilibration times required for low ionic strength acidic mobile phase.

The Shim-pack Arata Peptide C18 columns offer an excellent separation performance of peptides, even under weak ion pairing acidic mo­bile phases, and are therefore suitable for MS detectors. Since the adsorption of peptides to particles is minimized, the Shim-pack Arata Peptide C18 column ensures high recovery of peptides and provides excellent peptide analysis.

Shim-pack G series: for general applications

The Shim-pack G series consists of GIST, GISS and GIS, designed not only for conventional analysis but also for ultra-high speed and preparative methods due to their various particle size ranges. The Shim-pack GIST series includes standard columns for general ap­plications, while the Shim-pack GIS columns are especially suited for preparative chromatography and the Shim-pack GISS for MS analysis.

Shim-pack GIST series: ultra-high inertness and high durability

Shim-pack GIST series columns are packed with newly developed high-purity porous spherical silica. Superior inertness not only improves analytical precision but also increases the column lifetime. It provides symmetric peaks even for strong ionic compounds, and undesired adsorption and peak tailing are reduced to a minimum. It is capable of covering a wide pH range (1 – 10) and is therefore suitable for many applications.

Furthermore, the Shim-pack GIST series is designed with various par­ticle size ranges, making it easy to transfer any analysis from ultra-high-speed to conventional methods.

Compared to general C18 co­lumns, Shim-pack GIST C18-AQ achieves strong retention of hy­drophilic highly polar compounds while maintaining high inertness and durability in highly or 100 % aqueous mobile phases. Further­more, it reduces the absorption of basic and acidic compounds and achieves superior peak shapes in the analysis of metal complexes.

Shim-pack GISS Series: high-speed analysis with ultra-high inertness and high durability

The Shim-pack GISS series maintains the same ultra-high inertness and wider pH range as the Shim-pack GIST series while providing rapid separations with symmetric peaks. The optimization of surface area, pore size and chemical bonding delivers superior peak shapes, making these columns ideal for LC/MS/MS analysis. Shim-pack GISS series also includes the 1.9 µm and 3 µm HP series for UHPLC-analyses.

Shim-pack GIS Series: high retentivity, lower column back pressure, high inertness

These columns are packed with high purity silica gel and are ideal as generic HPLC columns. Highly uniform particles ensure stable mobile phase delivery and outstanding low pressure. The Shim-pack GIS columns not only help reduce solvent costs, but also relieve system load. In addition, the uniform silica surface and stable chemical modifications ensure high analysis reproducibility.

Shim-pack GIS C18-P is designed with a polymerically bonded octa­decyl group, providing high steric selectivity for separation of planar and non-planar compounds, such as vitamin D2/D3 or PAHs.

Shim-pack GIS RP-Shield contains a polar functional group embedded between silica surface and an octadecyl group, making it stable in 100 % aqueous mobile phases without phase collapse. The embedded polar functional group is also extremely base-deactivated, enabling the column to provide superior peak shape for acids. It also provides unique selectivity due to hydrogen bonding interactions, making it suitable for separations that cannot be achieved by other modes, such as hydrophobic interactions or π-π interactions.

Shim-pack MC: the perfect column for Micro LC

The Shim-pack MC columns are compatible with a range of mobile phase flow rates, from one microliter per minute to dozens of microliter per minute, making them the ideal columns for micro LC.

More information on Shimadzu’s C18 column range can be found at www.shimadzu.eu/hplc-columns