We feel very confident that there is virtually no Pt from the catalyst present in the stationary phase, as determined by both ESCA and chromatographic testing. We intentionally ran the bonding reaction at high catalyst concentration in order to actually reduce some of the Pt and deposit it on the Surface. This produced a Visual […]
Category: Phenyl Hydride FAQ
How can I separate methacrylic acid and dodecyl benzene sulfonic acid – FAQ
Good retention and peak shapes have been observed for similar compounds. Methacrylic acid is similar in structure to acrylic acid, which can be well-retained with a mobile phase of DI water + 0.1% formic acid and a Bidentate C18 column. Dodecyl benzene sulfonic acid has some of the same functional groups as docusate sodium, which also has […]
Suggestion for separation of phenylephrine HCl acetaminophen and dextromethorphan – Tips & Suggestions
The Cogent Phenyl Hydride™ would be recommended for these compounds because of dextromethorphan. It has a strong tendency to tail on most columns but the Phenyl Hydride™ column can produce a very symmetrical peak; a mobile phase additive of 0.1% TFA would be beneficial as well for reducing dextromethorphan peak tailing. Phenylephrine HCL does not […]
Use a low concentration of salt in your mobile phase to avoid ion suppression and build up on your inlet source – Tips & Suggestions
Many people ask me about the problem associated with polar acidic compound analysis using HILIC or ion exchange columns with Mass Spectrometry. Fortunately, there is an easy solution to this problem. You can use Cogent TYPE-C HPLC columns such as the Diamond Hydride™, Phenyl Hydride™ and others to separate highly polar compounds in Aqueous Normal […]
What is the structure of the Cogent Phenyl Hydride bonded ligand – FAQ
The Cogent Phenyl Hydride phase is a 4 carbon chain with a phenyl group at the end attached directly to the silica hydride surface with a single, direct silicon-carbon bond. With bonds in traditional silica B based materials, the organo-silane starting material is Si-O-Si-C4-Phenyl and this reagent is reacted with the silica to form the […]
Which Cogent TYPE-C column do you recommend for the separation of positional isomers with HPLC or LCMS – FAQ
The answer to this question depends on what type of positional isomers. For Reversed Phase separation of aromatic positional isomers, the Cogent Phenyl Hydride™ is often a good choice. These isomers may differ in their electron density of the aromatic ring due to the positions of the various substituents that may be present. These differences […]
Why are Aqueous Normal Phase ANP HPLC methods better to use than HILIC – FAQ
Why Aqueous Normal Phase ANP methods may be considered better than HILIC methods for the analysis of polar compounds with HPLC Compared to ANP, HILIC will require more time to equilibrate between gradient runs HILIC takes more salt to retain some compounds HILIC often lacks Retention Time RT precision HILIC cannot retain polar compounds with […]