CERI 711170 L-column2 ODS C18 Octadecyl HPLC Column, 2.1mm x 100mm, 3μm Particle Size
Average particle size: | 2µm, 3µm, 5µm |
Average pore size: | 120 Å |
Surface area: | 340 m2/g |
Carbon contents: | 17 % |
Bonded phase: | C18 (Octadecyl) |
End-capping: | Yes |
USP category: | L1 |
Range of pH: | pH 2 – pH 9 |
L-column2 ODS exceeds even the high performance of L-column ODS by virtue of its advanced new end-capping method. It accommodates the analysis of acidic, basic and chelating compounds.
- Sharper peaks for acidic, basic and chelating compounds due to extremely low silanol adsorption.
- Superior peak shapes in both acetonitrile/water and methanol/water mobile phases makes L-column2 ODSconvenient to use.
- Economical due to high durability in a wide range of pH and temperature.
- Uniform lot to lot reproducibility of analyses due to extensive quality control measures.
L-column series is the column for reversed-phase high-performance liquid chromatography (RP-HPLC) that enabled separation only by hydrophobic interaction because of inhibition of the secondary interaction with residual silanol groups and metal impurities. In 1990, the new end-capping method using high-temperature silylation was invented. The performance of L-column ODS developed using this method was far superior to that of existing C18 columns, and it became a pioneer of the new-generation end-capping method. L-column2 ODS, surpassing L-column ODS in performance, was developed by upgrading the end-capping method. There is now a demand for RP-HPLC columns capable of both handling various issues of trace analysis due to the popularization of LC/MS(/MS) and providing advanced analytical precision. L-column2 ODS is an ideal column for meeting this demand.
Characteristics of L-column2 ODS
- Sharper peaks for acidic, basic and chelating compounds due to extremely low silanol adsorption.
- Superior peak shapes in both acetonitrile/water and methanol/water mobile phases makes L-column2 ODS convenient to use.
- Economical due to high durability in a wide range of pH and temperature.
- Uniform lot to lot reproducibility of analyses due to extensive quality control measures
Residual silanol groups
The level of residual silanol groups is measured by FT-IR spectrum. The spectra of C18 without end-capping and the fully end-capped L-column2 ODS are shown (Fig. 2). The spectrum region for C-H and O-H provides quantitative information as well as qualitative identification. FT-IR spectra show virtually no presence of silanol groups on L-column2 ODS. In addition, the spectrum region for O-H (the right spectra) shows that L-column2 ODS has the least residual silanol groups of any column tested
Low adsorption
Basic compounds show peak tailing due to their adsorption by residual silanol groups. Therefore, adsorption is inhibited using an acidic mobile phase or a mobile phase including methanol to control peak tailing. Because the residual silanol groups show intrinsic activity using a neutral mobile phase or a mobile phase including acetonitrile as an organic solvent, peak tailing of basic compounds due to adsorption occurs when using poorly end-capped columns.
L-column2 ODS is perfectly end-capped, so it does not adsorb analytes using any composition of mobile phases and provides a superior peak shape. While peak tailing of basic compounds using a neutral mobile phase or a mobile phase including acetonitrile occurs with almost all C18 columns, peak tailing of basic compounds using these mobile phases does not occur with L-column2 ODS (Fig. 7). Therefore, it can be used in a wide range of compositions of mobile phases. This is an important point when selecting a column.
Improved durability
A durability test was carried out under high temperature conditions which accelerate deterioration of columns. L-column2 ODS was stable for the longest time. Although it is silica-based, it shows superior durability even under alkaline conditions due to the extremely dense end-capping.
[Accelerated acidic mobile phase lifetime test] Under acidic conditions, below pH1, both the end-capping group and the ODS group are hydrolyzed. Retention time decreases with the decrease of ODS groups. Resolution decreases with the progression of the hydrolysis. L-column2 ODS resists hydrolysis even under these harsh conditions to maintain retention and resolution for an extended lifetime.
Accelerated alkaline mobile phase lifetime test] Dissolution of the base silica is accelerated in alkaline mobile phase. Efficiency (theoretical plate number) drops suddenly in these conditions. L-column2 ODS has superior durability under high pH conditions (pH10) due to the protection of the silica surface afforded by the advanced end-capping process
Superior reproducibility
Variation between product lots due to residual silanol groups is prevented by superior end-capping. Although reproducibility of retention times of basic compounds is poor between product lots, the coefficient of variation of the retention times between the product lots is under 1% for L-column2 ODS (Fig. 10). Regardless of the product lot, L-column2 ODS provides the same results in HPLC analysis because of thorough quality control.