||ANP HPLC Replaces HILIC - With Benefits
Many chromatographers have been given the task to develop HPLC and LCMS methods for polar compounds. Those who have chosen HILIC columns often report their gradient methods are problematic causing them…
||Literature References for Cogent TYPE-C™ Silica Hydride Based HPLC Columns
The following is a list of articles published in peer-reviewed journals and books that discuss Cogent TYPE-C Silica™ based materials and their applications: Authors Title Publication Date Volume Pages…
||"Normal Conditions" for Cogent TYPE-C Silica columns
The Cogent TYPE-C Silica™ columns have been observed to last 20-50% longer than those based on ordinary silica under normal conditions. What this means is following the specifications of the columns…
||Amide vs. Amine/Amino HPLC columns
The amide functional group should not be confused with the amine or amino moiety. The presence of the carbonyl group imparts the amide functionality with significant physical and chemical differences…
||Are the Cogent TYPE-C Silica based stationary phases available as bulk materials?
No, the Cogent 4um and 2.o TYPE-C Silica™ based stationary phases are not available as unpacked bulk material. TYPE-C Silica™ is a very unique material and to properly pack columns or capillaries…
||Assuring retention of polar compounds in an ANP gradient in positive mode LCMS.
When using a Cogent Diamond Hydride™ column prepare your solvents for positive ionization in LC-MS: Solvent A: 50% methanol/50% DI water + 0.1% formic acid and Solvent B: 90% acetonitrile/10% DI water/0.1%…
||Can Cogent TYPE-C columns be used for high temperature analysis?
Cogent™ HPLC columns are made with state of the art, modular, column hardware. The frits are stainless steel inserted in a high quality PEEK cap device and positioned onto the column during manufacturing.…
||Can I use acetone as a mobile phase solvent in ANP?
If you are using LCMS, the simple answer is yes but pH is also something to consider. Acetone has a high UV cutoff and therefore can be a problem for UV detection. However, this is not a problem when…
||Can I use phosphoric acid or sodium phosphate with the Cogent Diamond Hydride HPLC column?
Yes, but there is some evidence that the use of phosphoric acid may semi-permanently change the surface chemistry, and therefore the chromatography of the column. For example, if you get a certain separation…
||Cleaning Cogent TYPE-C silica based HPLC columns
The Cogent TYPE-C™ HPLC columns are very stable and can be washed between runs with 100% Acetonitrile, DMSO THF and DMF among many other solvents. We use these solvents when typical washing procedures…
||Cogent Diamond Hydride 2.o™ Retention Time Precision
The following graph shows a study investigating the day to day retention time precision of two test solutes on the Cogent Diamond Hydride 2.o™ column. Many factors can affect column robustness and lifetime,…
||Development guide for ANP or Aqueous Normal Phase HPLC methods
Why ANP is better than HILIC for most polar compound methods HILIC will require more time to equilibrate, more salt to retain compounds, lacks RT precision and lifetime of the columns is short. With ANP…
||How does efficiency in ANP compare to HILIC?
Aqueous Normal Phase (ANP) is a distinctly different retention mode than Hydrophilic Interaction Liquid Chromatography (HILIC). In HILIC, evidence has shown that retention is achieved by partitioning…
||How to analyze phosphorylated compounds with the Cogent Diamond Hydride™ column
Phosphorylated compounds can be difficult to analyze by HPLC. However, a wide variety of compounds with the phosphate functional group have been able to be retained with the Cogent Diamond Hydride™…
||How to change columns from reversed phase to normal phase mode and vice versa
Just as a reminder, all Cogent TYPE-C™ columns are filled with water containing solvents during shipping. To start work in normal phase mode, a simple switching procedure is recommended. A simple 30…