Are Cogent TYPE-C Silica 2.o™ columns considered “UHPLC” phases?

The generally accepted definition for a UHPLC (Ultra High Pressure Liquid Chromatography) column is one in which the particle size is below 2 µm. Our Cogent TYPE-C Silica 2.o™ columns have an average particle size of 2.2 µm, making them “near-UHPLC” phases. The idea behind UHPLC columns is that, as particle size decreases, peak efficiency increases dramatically. […]

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Can I use 4um guard columns with the 2.o™ analytical columns?

We would recommend against using different particle sizes and stationary phasess for guard and analytical column combination. That being said, the Cogent 2.o™ columns are valuable so it may be worth trying and seeing if the guard column does or does not have an adverse effect on efficiency in the method. If the purpose of using a […]

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Cogent Diamond Hydride 2.o HPLC Column Retention Time Precision – AppNote

This Graph shows a Study Investigating the Day to Day Retention Time Precision with two test solutes on the Cogent Diamond Hydride 2.o™ HPLC Column. Peaks: Blue Trace: Phenylalanine Red Trace: Phenylglycine Many factors can affect Column Robustness and lifetime, so it is not possible to define specific values for those parameters. Mobile Phase: —A: DI […]

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How much higher is the pressure generated on the 2.o™ columns than standard 4um phases?

The column pressure under any conditions can be predicted using the following equation: P = (150 η L F) / (dparticle2 dcolumn2) where P is the pressure, η is the solvent viscosity, L is the column length, F is the flow rate, dparticle is the particle diameter, and dcolumn is the column inner diameter. If only the particle size is varied (same method, same column dimensions), then the factor (150 η L F) […]

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What Temperature Should I Use with The Cogent TYPE-C 2.o HPLC Columns?

We recommend a starting temperature of 25 °C for most applications. Generally you will see higher retention at higher temperatures and lower retention at lower ones with Aqueous Normal Phase (ANP) chromatography. This can sometimes be a useful tool for fine-tuning the retention/selectivity of the peaks. Although temperature is a variable to consider during method development, we […]

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