Reversed-phase Chromatography

ULTRON VX-ODS columns employ ULTRON VX-SIL as a substrate to which monomeric octadecyl groups are chemically bonded. Our unique end-capping technology (secondary silylation) leads to reductions in the influence of residual silanol groups. We provide three types of particle diameters (5, 10, and 15 μm). We also have a variety of columns with inner diameters ranging from 1 mm (narrow bore) to 50 mm (for preparative separations). Please select an appropriate column size according to your intended purpose.

Correspond to USP number L01: Octadecyl silane bonded to porous silica or ceramic microparticles, 3 to 10 micrometers in diameter.

PDF Download Reversed-phase Chromatography: Specifications and Prices

VX-ODS

Specifications

Particle Size	Pore Size	Specific Surface Area	Carbon Content
5μm	120A	300m²/g	16％

Features

Reproducibility between column lots

Reproducibility between column lots
ULTRON VX-ODS columns are checked using stringent quality control in each manufacturing process.
Only ULTRON VX-ODS columns that pass repeated testing during the manufacturing processes are shipped to customers. k' and α values obtained using ULTRON VX-ODS columns display only extremely small differences between lots. ULTRON VX-ODS columns also display excellent reproducibility and stability in other tests between column lots.
Stereoselectivity, distribution equilibria
ULTRON VX-ODS columns, which have monolayers of octadecyl groups, display excellent stereoselectivity with respect to sample molecules. Distribution equilibria are reached rapidly when performing gradient elutions and when mobile phases are changed.
Pressure resistance
Because ULTRON VX-ODS columns use spherical silica gel, they display excellent pressure resistance, and stable separations can be achieved even at fast mobile phase flow rates.

VX-ODS.G (guard columns)

Column life test using alkaline solution

Column life test using acidic mobile phase

ULTRON VX-Octyl

Global environmental problems are now the focus of a great deal of attention from around the world. We have to protect our earth against atmospheric, water, and soil pollution, as well as industrial waste pollution. In the area of HPLC technology as well, columns capable of performing analyses using smaller volumes of organic solvents will become necessary. Consequently, octyl columns with shorter analysis times than ODS columns and which can also maintain high separation capacities are beginning to take the place of ODS columns. ULTRON VX-Octyl columns possess the necessary characteristics to satisfy such requirements.
We have utilized the highly refined synthesizing technology used to manufacture ULTRON VX-ODS columns to produce the ULTRON VX-Octyl column.

Features

Column lifetimes have been greatly improved.
ULTRON VX-Octyl columns have very low variations between lots and display excellent reproducibility.
ULTRON VX-Octyl columns provide shorter analysis times than ODS columns and can also maintain high separation capacities.
Volumes of organic solvents can be reduced.
Because distribution equilibriums can be achieved quickly and adsorbed materials can be eluted easily in comparison with ODS columns, these columns are perfect for gradient elutions.

Applications

Pharmaceutical compounds, pesticides, chemical compounds, food products, environmental compounds, etc.

Life Test in Acidic Solution

Comparison of retention of alkylbenzenes in VX-Octyl and VX-ODS columns

Packed Columns for High Performance Liquid Chromatography
STR ODS-II

Corresponds to USP number L01: Octadecyl silane bonded to porous silica or ceramic microparticles, 3 to 10 micrometers in diameter.

Features

The effects of metal oxides are suppressed to a minimum due to the use of highly-purified silica gel as a base material in the STR series.
STR series columns are durable due to the use of mechanically strong silica gel.
STR series columns are highly resistant to acidic and basic mobile phases.
STR series columns are easy to operate and display high levels of performance due to low analytical operating pressures.
Excellent end capping technology provides sharp peak shapes for basic and acidic compounds, and for samples which form complexes with metals.

Column	Particle Shape	Particle Size	Pore Size	Specific Surface Area	Carbon Content
ODS-II	Spherical porous silica gel	5μm	12 nm	320m²/g	17％

Pressure drop

In general, analytical pressures rise in the case of eluents used in water-methanol systems. Higher analytical pressure drops cause reductions in column lifetimes and excessively long analytical times due to the inability to flow large volumes of mobile phase. In comparison with regular ODS columns, STR ODS-II columns have extremely low analytical pressures and are easy to use.
The figure below shows analytical pressures when aqueous solutions of methanol and acetonitrile are used as eluents.