Chiral pollutants analysis

Advances in Chiral Pollutants Analysis by Capillary Electrophoresis... 

I. Ah, H.Y. Aboul-Enein, Chiral pollutants Distribution, toxicity and analysis by chromatography and capillary electrophoresis, Chichester, UK John Wiley Sons (2004). 

As in the case of chromatography, a chiral selector is also required in CE for enantiomeric resolution. Generally, suitable chiral compounds are used in the background electrolyte (BGE) as additives and hence are called chiral selectors or chiral BGE additives. There are only a few publications available that deal with the chiral resolution on a capillary coated with the chiral selector in CE. The analysis of the chiral pollutants discussed in this chapter is restricted only to using chiral selectors in the BGE. The most commonly used chiral BGE additives are cyclo-dextrins, macrocyclic glycopeptide antibiotics, proteins, crown ethers, ligand exchangers, and alkaloids.A list of these chiral BGE additives is presented in Table 1. 

Capillary electrophoresis has been used for the analysis of chiral pollutants, e.g., pesticides, polynuclear-aromatic hydrocarbons, amines, carbonyl compounds, surfactants, dyes, and other toxic compounds. Moreover, CE has also been utilized to separate the structural isomers of various... 

Today, chromatographic modalities are used frequently for the analysis of chiral pollutants. The wide application of HPLC is due to the development of various chiral stationary phases and excellent reproducibility. However, ... 

Analysis of the chiral pollutants at trace levels is a very important and demanding field. In recent years, capillary electrophoresis has been gaining importance in the direction of chiral analysis of various racemates. A search of the literature cited herein indicates a few reports on the chiral resolution of environmental pollutants by CE. It has not achieved a respectable place in the routine chiral analysis of these pollutants due to its poor reproducibility and to the limitations of detection. Therefore many scientists have suggested various modifications to make CE a method of choice. To achieve good reproducibility. 

In addition, some other aspects should also be addressed so that CE can be used as a routine method in this field. The most important points related to this include the development of new and better chiral selectors, detector devices, and addition of a cooling device in the CE apparatus. In addition, chiral capillaries should be developed and the CE device should be hyphenated with mass spectrometer, polarimetric, and circular dichroism detectors, which may result in good reproducibihty and improved limits of detection. The advancement of CE as a chiral analysis technique has not yet been fiilly explored and research in this direction is currently underway. In summary, there is much to be developed for the advancement of CE for the analysis of chiral pollutants. It is hoped that CE will be recognized as the technique of choice for chiral analysis of the environmental pollutants. 

Aboul-Enein, H. Y, Ali, I. Analysis of the chiral pollutants by chromatography, Toxicol. Environ. Chem., 2004, 86, 1-22. 

Table 4 Selected GCxGC applications involving the analysis of chiral pollutants. For simplicity, only optimised experimental set-ups or those providing the most conclusive results have been mentioned (Acronyms as in Table 1)... 

Analysis of chiral pollutants by capillary electrophoresis (CE) is a new trend in separation science. This entry describes separation and identification of chiral xenobiotics by using CE. Attempts have been made to describe types of chiral selectors, applications, optimization of separations, detection strategies, mechanisms of chiral separations, CE vs chromatography and sample preparation methods. 

CE has been used for the analysis of chiral pollutants, e.g., pesticides, polynuclear aromatic hydrocarbons, amines, carbonyl compounds, surfactants, dyes, and other toxic compounds. Moreover, CE has also been utilized to separate the structural isomers of various toxic pollutants such as phenols, polyaromatic hydrocarbons, and so on. Sarac, Chankvetadze, and Blaschke " resolved the enantiomers of 2-hydrazino-2-methyl-3-(3,4-dihydroxyphenyl)propanoic acid using CD as the BGE additive. The CDs used were native, neutral, and ionic in nature with phosphate buffer as BGE. Welseloh, Wolf, and Konig investigated the CE method for the separation of biphenyls, using a phosphate buffer as BGE with CD as the chiral additive. Miura et al., used CE for the chiral resolution of seven phenoxy acid herbicides using methylated CDs as the BGE additives. Furthermore, the same group resolved 2-(4-chlorophenoxy) propionic acid (MCPP), 2-(2,4-dichlorophenoxy) propionic acid (DCPP), (2,4-dichlorophenoxy) acetic acid (2,4-D), 2-(4-chlorophenoxy) propionic acid (2,4-CPPA), [(2,4,5-... 

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