Agilent 1290 Infinity II is stated to be a universal system that is compatible for any HPLC or UHPLC applications. The Cogent 2.o™ HPLC columns are considered “near UHPLC” with pressure limits approximately 9,000 psi. If you are using Aqueous Normal Phase (ANP) HPLC it is unlikely you will develop such high pressure. Note: The […]
Category: 2.o™ HPLC Columns FAQ
Are Cogent TYPE-C Silica 2.o™ columns considered “UHPLC” phases? – FAQ
The generally accepted definition for a UHPLC (Ultra High Performance Liquid Chromatography) column is one in which the particle size is below 2 µm. The 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 […]
Can I use 4um guard columns with the 2.o™ analytical columns? – FAQ
We would recommend against using different particle sizes and stationary phases for guard and analytical column combination if you can avoid it. That being said, the Cogent 2.o™ columns are valuable so it may be worth trying and seeing if the 4um guard column does or does not have an adverse effect on efficiency in […]
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 […]
Differences Between Cogent Diamond Hydride 4um and 2.o Columns.
In terms of storage, conditioning, and general use, the same protocols can be used for the Cogent Diamond Hydride 4um and Cogent Diamond Hydride 2.o™ products. The main difference between the two is of course particle size. Cogent Diamond Hydride Product Page
How do Retention and Efficiency of Asymmetric Dimethylarginine, ADMA Compare Using 4um vs. 2.o™ Diamond Hydride™ Columns?
ADMA can be retained using an ANP gradient method with the Cogent Diamond Hydride™ HPLC column. Retention times for ADMA differed only slightly between the 4um and 2.o™ stationary phases. Efficiency however was notably higher when using the 2.o™ phase. This can be readily observed from the greater peak height using the 2.o™ column in the […]
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) […]
What Pressure Should I Expect with a Diamond Hydride 2.o HPLC Column at Flow Rates From 0.2-2.0 mL/min?
The below data was recorded on a Waters UPLC™ system. Please note that the pressure can vary widely depending on such factors as mobile phase viscosity, temperature, column ID, and column length. The conditions shown below should clarify any questions you may have regarding this data. Column: Cogent Diamond Hydride™, 2.2um 120A, 2.1 x 50mm, cat# […]
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 […]