Frequently Asked Questions about Cogent Qx2™ Quick HPLC Columns
- Will these columns have enough theoretical plates for a separation?
- Will these columns dry out?
- Is the Qx2 totally inert?
- Who is the manufacturer of the silica that is used in Cogent™ HPLC columns?
- How do I use Aqueous Normal Phase with the Cogent Qx2™?
- Most acids and bases are not effective when the organic content of the mobile phase goes too high. Since I am interested to use the Cogent columns in ANP, what can I do to adequately "acidify" the mobile phase when organic is higher than 40%?
- How do I use Methyl Phosphonic Acid in my mobile phase?
- Is Methyl Phosphonic Acid compatible with UV and MS detectors?
1. Will these columns have enough theoretical plates for a separation? [top]
If you are looking for a fast, easy to use HPLC column for LCMS or “Fast Chromatography” these columns may be the best
choice for your use and will have enough theoretical plates. This column format is supplied with actual test chromatograms
which shows how efficient these columns are. The direct connection feature of the Qx2 eliminates post column band broadening
due to extra column volume allowing for shorter faster runs.
2. Will these columns dry out? [top]
Even if your column does dry out, it will not damage it unless you allow it to dry out in a buffered mobile phase.
3. Is the Qx2™ totally inert? [top]
All of the wet-able surfaces of the Cogent Qx2™ are either Titanium or PEEK. The sample never comes in contact with any
other materials once inside the column.
4. Who is the manufacturer of the silica that is used in Cogent™ HPLC columns? [top]
MicroSolv Technology is the sole source and producer of the silica used in HPS™ HPLC Columns. The silica is manufactured
with proprietary sol-gel technology and quality controlled for purity and physical characteristics. The bonding process is
organo-silane with extensive, double end capping.
5. How do I use Aqueous Normal Phase with the Qx2™? [top]
One of the most unique features of the Qx2™ packing materials is that they will perform Aqueous Normal Phase. That
means at high Acetonitrile content (70% or above) of the mobile phase, acids and bases will retain on the column. This is
very desirous for Mass Spec where the sensitivity of your method will be increased with high organic content instead of high
aqueous. For more information on how this works, see How To Use TYPE-C Based Phases.
6. Most acids and bases are not effective when the organic content of the mobile phase goes too high. Since I am interested to use the Cogent columns in ANP, what can I do to adequately "acidify" the mobile phase when organic is higher than 40%? [top]
We have had some good success with methyl phosphonic acid. It remains soluble in acetonitrile content as high as 96%. This
might help when some compounds are retaining in ANP but the peak shape needs to be tightened up a bit.
7.How do I use Methyl Phosphonic Acid in my mobile phase? [top]
You could add 1ml/L into the mobile phase. Add more or less as desired.
8.Is Methyl Phosphonic Acid compatible with UV and MS detectors? [top]
Yes, Methyl Phosphonic Acid, when used in dilute conditions as described above, is UV transparent and is volatile. Therefore you can
use it with UV or MS detectors.
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