China 
Africa 
Explore chapters and articles related to this topic
Determinative Techniques to Measure Organics and Inorganics
Published in Paul R. Loconto, Trace Environmental Quantitative Analysis, 2020
We next consider a determinative technique introduced during the late 1980s and commercialized during the 1990s to the arsenal of instrumental analysis relevant to TEQA—capillaryelectrophoresis (CE). Our discussion of CE forces us to return to the separation sciences. CE encompasses a number of distinct modes: Capillary zone electrophoresis (CZE)Capillary gel electrophoresisMicellar electrokinetic capillary chromatography (MEKC)Capillary electrochromatography (CEC)Capillary isoelectric focusingCapillary isotachophoresis.
Determination of Pesticides in Water
Published in José L. Tadeo, Analysis of Pesticides in Food and Environmental Samples, 2019
Rosa Ana Pérez, Beatriz Albero, José L. Tadeo
Capillary electrophoresis (CE) is an alternative analytical technique that is complementary to GC and LC and has been applied in the determination of pesticide residues in water samples. The most frequently used working mode by CE is micellar electrokinetic chromatography (MECK), although capillary zone electrophoresis and capillary electrochromatography are also applied. Some examples of the application of MECK for the determination of pesticides in water samples are the methods developed by Santalad et al. [94] and Amelin et al. [95] using this technique in combination with SPE and/or DLLME for the determination of 6 carbamates pesticides and 38 polar pesticides in water samples, respectively. The application of sensors and biosensors in the determination of pesticides in environmental samples is also rapidly increasing. The main characteristics of these technologies and their application to pesticide analysis are included in Chapter 4. A recent example of the application of sensors is the method reported by Figueiredo-Filho et al. [87] in which a bismuth film on a disposable minisensor was developed for the determination of two dipyridyl pesticides (diquat and paraquat) using voltammetric techniques.
Recent Developments in Manufacturing Micro- and Nanoparticles from Emulsion Droplets
Published in Victor M. Starov, Nanoscience, 2010
Goran T. Vladisavljević, Richard A. Williams
Uniform polymer microspheres with the mean diameter ranging from several micrometers to 100 μm, hydrophilic and hydrophobic, smooth and rough, solid and hollow, porous and uniform, with different morphologies (spherical, snowman-like, popcorn-like, and hemispherical) were manufactured from O/W emulsions via SPG membrane emulsification followed by suspension polymerization (Omi, 1996). These microspheres were investigated for use as packing material for column chromatography techniques such as gel permeation chromatography (GPC), high-performance liquid chromatography (HPLC), capillary electrochromatography and size-exclusion chromatography, pH sensors, carriers of enzymes (glucoamylase), drug delivery systems, dry and liquid toners, spacers for liquid crystal displays, and so on (Vladisavljević and Williams, 2005).
Minireview: Recent advances in the determination of flavonoids by capillary electrophoresis
Published in Instrumentation Science & Technology, 2018
Tingni Wu, Changzhu Yu, Rong Li, Jun Li
CE is a powerful separation tool with multiple separation modes, including capillary zone electrophoresis (CZE), micelle electrokinetic capillary chromatography (MEKC), microemulsion electrokinetic chromatography (MEEKC), gel capillary electrophoresis, capillary iso-electric focusing, capillary isotachophoresis, and capillary electrochromatography (CEC). So far, the main modes used in separation of flavonoids are CZE and MEKC. Through the literature in recent 10 (2008–2017) years from PubMed and web of science, CZE, MEKC, MEEKC, and CEC were applied for the detection of flavonoids. This article introduces the specific applications in a variety of different situations.
PolyHIPEs for Separations and Chemical Transformations: A Review
Published in Solvent Extraction and Ion Exchange, 2019
Kathryn M. L. Taylor-Pashow, Julia G. Pribyl
There have been several reports on the use of polyHIPE materials for chromatography applications, specifically small-molecule separations. Work discussed in this section includes typical liquid chromatography as well as several examples of capillary electrochromatography (CEC) for small-molecule separation. A number of the papers focus on the separation of various alkylbenzenes with polyHIPE materials. In work by Tunç et al., monolithic polyHIPE columns were prepared by the in situ polymerization of isodecylacrylate (IDA) and DVB in fused-silica capillaries whose inner walls had been derivatized with 3-(trimethoxysilyl)propyl methacrylate.[33] The chromatographic performance of the resulting monolith was investigated by studying the separation of alkylbenzenes using CEC. The material showed successful chromatographic performance in the separation of the alkylbenzenes, notably without the use of an electroosmotic flow (EOF) generating monomer (theoretical plate number (TPN) of up to 200,000 plates/m). The reason that an EOF monomer was not needed is likely due to the presence of ionizable sulfate groups that are generated by the decomposition of the initiator (K2S2O8) during the HIPE polymerization. These groups likely provide sufficient charge to generate the EOF. To investigate this, polyHIPEs were prepared with varying amounts of initiator (ranging from 0.1 to 0.4 wt %), and electrophoretic mobility was shown to increase with increasing concentration of K2S2O8. A later report by the same group also described the use of a polyHIPE material for CEC separation of alkylbenzenes (TPN of up to 142,000 plates/m).[34] In this work, however, the polyHIPE backbone was prepared from polystyrene crosslinked with DVB. Similar to the earlier work, no EOF generating monomer was required, and instead the sulfate groups formed by the K2S2O8 initiator served as ionizable groups.