Capillary electrophoresis environmental analysis

SPE employing either GCB [6,25,73-75,80,81], C8 [77], C18 [82-87] or a combination of Cis- - SAX [88-91] cartridges is the most used method to determine SPC in environmental samples accompanied by detection with HPLC-FL [6,25,90], LC-MS [73-75,82,83,86], GC-MS with derivatisation [77,80,92] or capillary electrophoresis [81]. For biota samples, matrix SPE [85] or Soxhlet [91] followed by clean-up with SPE have been used to determine SPC. SPE employing GCB cartridges and further analysis by LC-MS has been used for the determination of SPDCs [73,74],... 

The hyphenation of CE and NMR combines a powerful separation technique with an information-rich detection method. Although compared with LC-NMR, CE-NMR is still in its infancy it has the potential to impact a variety of applications in pharmaceutical, food chemistry, forensics, environmental, and natural products analysis because of the high information content and low sample requirements of this method [82-84]. In addition to standard capillary electrophoresis separations, two CE variants have become increasingly important in CE-NMR, capillary electrochromatography and capillary isotachophoresis, both of which will be described later in this section. 

Dedicated applications of capillary zone electrophoresis (CZE) coupled to MS are discussed, particularly in the field of drug analysis. Development of other capillary-based electrodriven separation techniques such as non-aqueous capillary electrophoresis (NACE), micellar electrokinetic chromatography (MEKC), and capillary electrochromatography (CEC) hyphenated with MS are also treated. The successful coupling of these electromigration schemes with MS detection provides an efficient and sensitive analytical tool for the separation, quantitation, and identification of numerous pharmaceutical, biological, therapeutic, and environmental compounds. 

There are few methods which can measure well-defined metal fractions with sufficient sensitivity for direct use with environmental samples (approach B in Fig. 8.2). Nevertheless, this approach is necessary in the experimental determination of the distribution of compounds that are labile with respect to the time scales of the analytical method. Recent literature indicates that high-performance liquid (HPLC) and gas chromatographic (GC) based techniques may have such capabilities (Batley and Low, 1989 Chau and Wong, 1989 van Loon and Barefoot, 1992 Kitazume et al, 1993 Rottmann and Heumann, 1994 Baxter and Freeh, 1995 Szpunar-Lobinska et al, 1995 Ellis and Roberts, 1997 Vogl and Heumann, 1998). The ability to vary both the stationary and mobile phases, in conjunction with suitable detector selection (e.g. ICP-MS), provides considerable discriminatory power. HPLC is the superior method GC has the disadvantage that species normally need to be derivatised to volatile forms prior to analysis. Capillary electrophoresis also shows promise as a metal speciation tool its main advantage is the absence of potential equilibria perturbation, interactions... 

A high-sensitivity cell for the Agilent Capillary Electrophoresis System has recently been developed. The cell increases detection sensitivity by an order of magnitude compared to standard detection [61]. This new cell is expected to increase substantially the utility of CE/CEC for the detection of enantiomeric purity of chiral drugs and trace analysis in biological and environmental samples. 

Detection techniques of high sensitivity, selectivity, and ease of coupling with sample preparation procedures are of special interest for measuring PGM content in biological and environmental samples. ICP MS, electrothermal atomic absorption spectrometry (ET AAS), adsorptive voltammetry (AV), and neutron activation analysis (NAA) have fotmd the widest applications, both for direct determination of the total metal content in the examined samples and for coupling with instrumental separation techniques. Mass spectrometry coupled with techniques such as electrospray ionization (ESI) and capillary electrophoresis (CE) (e.g., ESI MS", LC ESI MS", LC ICP MS, CE MS", and CE ICP MS) offer powerful potential for speciation analysis of metals. MS is widely used for examination of the distribution of the metals in various materials (elemental analysis) and for elucidation of the... 

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. 

Valsecchi, S.M. Polesello, S. Analysis of inorganic species in environmental samples by capillary electrophoresis. J. Chromatogr., A 1999, 834, 363-385. 

Parves, H., P. Candy, S. Parvez, and P. Roland-Gosselin, Capillary Electrophoresis in Biotechnology and Environmental Analysis, VSP, Utrecht, 1997. 

Marcel Dekker, Inc. All rights reserved. This material may not be used or reproduced in any form without the express written permission of Marcel Dekker, Inc. 2 Environmental Pollutants Analysis by Capillary Electrophoresis... 

Martinez, D. Cugat, M.J. BorruU, E. CaluU, M. Solid phase extraction coupling to capillary electrophoresis with emphasis on environmental analysis. J. Chromatogr. A 2000, 902, 65-89. 

Within the last 25 years, capillary electrophoresis (CE) has developed as a high-resolution analytical technique that has been apphed to all analytical helds including chemical, pharmaceutical, biomedical, forensic, environmental analysis, and food sciences. Based on the number of publications, drugs are actually the preferred analytes in CE. While they served as model compounds for the investigation of specific aspects in some studies, CE has been used to solve real pharmaceutical problems in the majority of applications. 

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