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Cogent Diamond Hydride

1 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…

2 Can I use ion-pairing with the Cogent Diamond Hydride HPLC column?

Ion-pairing will not work with the Diamond Hydride column. It separates on the basis of polarity. Using an ion-pairing reagent reduces that polarity so the compound can be separated on a reversed-phase…

3 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…

4 Can I use the Cogent Diamond Hydride™ column without mobile phase additives (e.g. formic acid)?

Using only acetonitrile and water and no additives is fully compatible with the column and will not damage it. We might however recommend having 0.1% formic acid during column storage to help inhibit…

5 Cocaine & metabolite Ecognin, HPLC column suggestion.

We are looking for a column capable of separating cocaine and its metabolites particularly Ecgonin which is very polar. The remaining metabolites (BE, EME, etc.) are less polar. The idea would be to separate…

6 Differences between Cogent Diamond Hydride™ 4um and 2.o™ products

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…

7 How can I restore my Diamond Hydride HPLC column? I ran out of mobile phase in my B solvent and air was accidently introduced into it and my analytes are not retaining now.

Although you should never let any HPLC column dry out, your column is probably not ruined. However, It could take days to get it restored when conditioning it with your mobile phase. If there is air in…

8 How do I avoid distorted peak shape when using a basic mobile phase pH for HPLC analysis of a lipophilic amine?

You may not require a basic mobile phase pH for HPLC analysis of these types of analytes. Use of the Cogent Diamond Hydride™ column in ANP mode with 0.1% formic acid instead of a basic mobile phase…

9 How do I condition Diamond Hydride columns when I use them for serum samples?

For serum (and other biological samples) we recommend using: Solvent A: 50% DI water/50% methanol (or 2-propanol) + 0.1% formic acid (for positive mode) or +10 mM ammonium acetate or formate (for negative…

10 How do I condition new Cogent TYPE-C™ Columns for use?

For all new Cogent TYPE-C™ HPLC columns with the exception of new Diamond Hydride™ columns, all one needs to do is run 7-10 column bed volumes of your mobile phase through the column at your normal…

11 How do you maintain and store the Cogent Diamond Hydride column?

Conditioning steps depend on the samples: Before first use, condition the column with 50:50 MeOH/Water for 30 min. 1. Urine, plasma, or other biological samples, etc: A. Conditioning with 80% acetonitrile/…

12 How often do I need to do the conditioning procedure for a new Diamond Hydride column?

The Diamond Hydride™ column comes with an insert that describes initial conditioning steps that should be done when you first receive the column. These washings usually only need to be done once to…

13 I am not observing any peaks for succinic acid or alpha-ketoglutarate with the Cogent Diamond Hydride column in my LCMS runs.

Question: I am using LC-MS with positive ionization mode and the Diamond Hydride column. My mobile phase has 0.1% formic acid in A and B solvents. However, I see no peaks for succinic acid and alpha-ketoglutarate…

14 I am using a Cogent TYPE-C™column with LC-MS and solvents containing 10 mM ammonium acetate. I noticed that my source was getting white film on it. At the same time the background noise was very low. Is my column bleeding the packing material?

Cogent TYPE-C™ columns including the Cogent Diamond Hydride have a very low background noise even when used with LC-MS and the white film most likely comes from ammonium acetate build up from your mobile…

15 I see a white film developing on my MS source after doing LCMS. How do I know I'm not losing packing material?

If the film was from dissolved stationary phase material, you would see a significant distortion in peak shape for all your analytes due to the void that would be developing in the column. If it was from…

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