Stationary phases metal-containing

Some selected applications (chemical class, mobile phase, stationary phase, column, detector) are as follows fatty acids, C02, PEG or CN-PS, OTC, FID organotin, C02, PhMe-PS, OTC, FPD [305], ThepSFC-ICP system is an effective tool for speciation of metal-containing compounds [362], even in the presence of modifiers to control the retention of components. 

In TLC, the sample is applied as a small spot or streak to the marked origin of stationary phase supported on a glass, plastic, or metal plate. The sample solvent is allowed to evaporate from the plate that is then placed in a closed chamber containing a shallow pool of mobile phase at... 

What is the reason for the overwhelming acceptance of stationary phases based on high-purity silicas in the pharmaceutical industry The answer is simple superior peak shapes for analytes with basic functional groups, which has been a problem with older phases. The older, low-purity silicas contain metal ions buried in the matrix of the silica. These contaminants acidify the surface silanols, and the consequence is a strong and non-uniform interaction with basic analytes. This in turn results in tailing peaks, which is an impediment for accurate peak integration and peak resolution. Of course, adding appropriate additives, such as amine modifiers, to the mobile phase can solve these difficulties. But this is an unnecessary and undesired complication in methods development. Therefore, silicas that are free from this complication are much preferred. 

Although the majority of reports of macrocycles in analytical chromatography have involved ligand association with the stationary phase, their use as mobile phase constituents has also been investigated. Lamb and Drake [11] showed that addition of water-soluble crown ethers to the mobile phase altered the retention of alkali metal cations on an underivatized reversed phase column. Nakagawa et al. [63-66] also used crown ether-containing mobile phases in the separation of protonated amines, amino acids and peptides, and [1-lactam antibiotics. 

Kimura, K., Hayata, E., and Shono, T. (1984) Convenient, efficient crown ether-containing stationary phases for chromatographic separation of alkali metal ions dynamic coating of highly lipophilic crown ethers on octadecylsilanized silica, Chem. Commun., 271-272. 

The application of stationary phases containing metal coordination compounds to the GC separation of organic substances has been the subject of many publications and... 

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