Frequently Asked Questions About Cogent hQ
- What is Cogent hQ?
- What is the pH Stability of Cogent hQ?
- What is the column to column reproducibility?
- Who is the manufacturer of the silica that is used in Cogent HPLC columns?
- How long have Cogent hQ HPLC products been on the market?
- Why would I use a non end-capped HPLC Column?
1. What is Cogent hQ? [top]
Cogent hQ is a state-of-the-art stationary phase that is designed for applications with polar compounds. The metal
content in Cogent hQ is extremely low and this produces very good stability and “deactivates” the silica for use with polar
analytes. A very smooth and uniform silica surface results for mechanical strength and stability. Due to the high purity and
the proprietary bonding technology, these columns are not end-capped leaving residual silanols for increased retention of
polar compounds with good peak shape for many compounds that will not retain well on end-capped columns.
Cogent hQ is available for HPLC with C18 or C8 stationary phases.
2. What is the pH stability of Cogent hQ? [top]
These columns are extremely stable for non end-capped columns and the range is in from pH 1.7 to pH 6.0. Depending on the
concentration of the acid or base will determine if these columns would be stable outside of this range.
3. What is the column to column reproducibility? [top]
These columns have been determined to be very reproducible from column to column, from batch to batch by customers from all
parts of the world.
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 hQ 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 and no end-capping is performed.
5. How long has Cogent hQ been on the market? [top]
The Cogent hQ product line has been on the market since April 2001.
6. Why would I want to use a column that is not end-capped? [top]
End-capping is a great idea for neutral and non polar compounds that are hydrophobic. Sometimes, polar compounds do not
retain well enough on end-capped columns but will retain and separate on non end-capped due to the increased polar nature of
the stationary phase. Due to the very high purity of the Cogent hQ silica, these columns are remarkably stable in the
pH range that they are intended for (1.7-6.0) and may make your search for a column to retain your polar analytes end with
this C18 or C8 column.