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FAQ

What is the pressure rating of your columns?

All analytical (25cm x 4.6 mm i.d.) and semi-preparative (25cm x 10.0 mm i.d.). columns manufactured by Regis can tolerate pressures up to 6000 psi. Larger columns will tolerate 3000 psi. It is very important not to exceed the maximum pressure rating for any HPLC column as you may disrupt the integrity of the silica bed and destroy the column.


Frequently Asked Questions

Listed here you will find some of the frequently asked questions. By no means is this a complete list, if you have questions regarding chiral chromatography, please feel free to contact us.

Can Regis columns be reversed?

Yes, all columns packed by Regis are fully reversible. In fact, Regis was the first column manufacturer to sell a fully reversible HPLC column. It is recommended to reverse your column frequently. This helps keep the frit surface from becoming clogged with undissolved sample or particulates in the mobile phase, thus extending the column life..


What is the pH range of your columns?

All of Regis’ Chiral phases are bonded on silica. The recommended pH range is 2.5 to 7.5. Limited usage outside of this pH range can be tolerated, but it has been proven that extended usage outside of the range will decrease column life..


Chiral Chromatography

Answers to the FAQ are very generalize and not specific, differ case to case.

Can your columns be used in normal and reversed-phase solvents?

Yes, all Pirkle-Type Chiral HPLC columns can be used in BOTH normal and reversed-phase solvents. Generally, the Pirkle-Type CSP’s will give better separations by using them with normal-phase solvents. There are numerous examples, however; where separations with reversed-phase solvents will outperform those with normal-phase solvents


What is the difference between Whelk-O 1 and Whelk-O 2?

Although the Whelk-O 1 and Whelk-O 2 both share the same Chiral selector, they have distinct differences. The Whelk-O 1 is monofunctionally bonded to silica and the Whelk-O 2 is trifunctionally bonded. The Whelk-O 2 was designed to tolerate strong acidic modifiers such as TFA. The Whelk-O 2 was designed for preparative use and is not available on 5-micron silica. Due to the fact the Whelk-O 2 is a trifunctional bond, coverage on the silica will be less than with Whelk-O 1. This decrease in the actual number of bonded sites will decrease selectivity and not allow for exact reproducibility of a method developed on a Whelk-O 1 column.


What sampling loading can I expect from Pirkle-Type Chiral HPLC columns?

The typical loading range – with relative retention’s (alpha) greater than 1.3—is ~ 4-16 mg of sample per gram of packing. Below are typical loadings for some of the different column sizes: Note: Factors, such as solubility, will greatly affect loading capacity. Analytical column, 25cm x 4.6mm, ~ 3.5 grams of packing, loading is 14-56 mg/ injection. Semi-prep column, 25cm x 10.0mm, ~ 16 grams of packing, loading is 64-256 mg/ injection. Prep column, 25cm x 21.1mm, ~ 72.5 grams of packing, loading is 288-1,152 mg/ injection.

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