Efficient separation methods

The development of bioreactor systems for the production of large-volume chemicals (see Chapter 3) could be the basis for reconsidering the production of biomass in limited quantities for fuel uses. This would require efficient microbial organisms to catalyze fermentation, digestion, and other bioconversion processes, as well as efficient separation methods to recover fuel products from process streams. 

The use of building materials, furniture, carpets and household products produces an almost ubiquitous level of volatile organic compounds (VOCs) in indoor air. Several hundred different compounds have been identified in the indoor environment. Since most air pollutants occur in low concentrations of 1-1000 rg/m3, highly sensitive detection methods as well as efficient separation methods are needed to analyze air samples (Barro et al., 2009). 

Micellar electrokinetic chromatography has been proven to be a highly efficient separation method for neutral analytes (63,67,68), neutral and charged compounds (69-72), and ionized compounds (67,73) including PTH-amino acids (18). 

Tennikova, T. B., and Svec, F. (1993). High-performance membrane chromatography Highly efficient separation method for proteins in ion-exchange, hydrophobic interaction and reverse-phase modes. J. Chromatogr. 646, 279-288. 

There has been much interest in the analysis of nucleosides, nucleotides, and modified nucleosides. Qualitative and quantitative analysis of these compounds in biological fluids provides valuable information for the diagnosis of diseases and metabolic disorders. Several reports indicate that CEC is very suited for these types of analyses, as faster and more efficient separation methods are demonstrated. 

Over the years, several technologies, inspired by differing ideas, have been developed to treat radioactive waste streams. Some of them are based on efficient separation methods that remove radioactive contaminants from the waste streams to reduce radiological... 

This is the only analytical field where high-US agglomeration has been tested and its potential as an efficient separation method — which some authors deem "filtration" or "filterless US-assisted filtration mode" — exploited [75]. 

Centrifugation is an efficient separation method for research into destabilization and the following aggregation of HS molecules as well as for the optimization of chemical parameters for coloured water treatment. 

As chromatography is the most efficient separation method which can be applied to these samples, it has been shown that the on-line coupling of such columns can successfully apply to water analysis [ 35 ]. This method is derived from the multi-dimensional gas chromatography (MDGC) technique. Double oven instruments were recently developed which are specifically dedicated to this type of MDGC analysis [36]. 

Although the hypochlorite method we previously elaborated conveniently produces carbonylbisphosphonate esters under very mild conditions, it suffers from two potential drawbacks 1) the exothermicity and exponential increase in rate of reaction, so convenient on small scale, might pose cooling and control problems on major scale-up 2) thus far, an efficient separation method to remove the small amount of dichlorinated side product always present, has not been found. 

Thanks to the development of microanalytical techniques and efficient separation methods, it is now possible to determine the structure of a biofunctional molecule with less than 1 mg of the material. In Table 1.2, examples are given with regard to the amounts of the samples employed for the structure elucidation of biofunctional molecules. 

Pyrolysis-gas chromatography (Py-GC) Thermal decomposition is one of the oldest methods for studying the composition of polymers, and is a valuable tool in the industrial analysis of plastics. The analytical use of Py-GC is based on the fact that the polymer structure determines its reactivity and thus also the qualitative and quantitative composition of the pyrolysis products. The technique combines the advantages of a highly efficient separation method with a directly connected pyrolysis unit, so that the degradation products can be analyzed immediately after their formation. Curie-point pyrolyzers yield the most reproducible results due to short temperature... 

The increasing technological significance of lanthanides will continue to pave the way for development of rapid and efficient separation methods with sensitive detection. Several reviews on lanthanide analysis indicate the importance of these materials and the need for the development of new and better techniques. Many HPLC based techniques have been developed for the separation of individual lanthanides using cation exchange, dynamic ion-exchange methods, etc. The selection of gradient elution techniques has been... 

Bio-oil, a kind of biofuel, could be obtained by flash pyrolysis of biomass. Because bio-oil is a type of complex mixture, some researches about bio-oil separation have been conducted in the recent years. Xianwei Zheng et al. have successfully separated flash pyrolysis oil into four kinds of substances by united extraction and distillation. Garcia-Perez et al. have provided an efficient separation method by using five kinds of solvent extraction, and bio-oil was separated into six kinds of substances. 

The lanthanide family of elements has played an important role which can be expected to continue in the development of coordination chemistry. In the early history of these elements, their close chemical similarity in the stable tripositive oxidation state made the task of achieving high purity for individual elements very difficult Although the entire lanthanide series had been discovered by 1907 (with the exception of Pm) and mixtures of lanthanides had been found in more than a hundred minerals, it was not until efficient separation methods were developed that detailed and diverse studies of their coordination chemistry could be undert en. 

Besides on-line TLC application from GC, supercritical fluid extraction (SFE) or TAS (thermal separation technique), the on-line coupling of HPLC with automated multiple development (AMD) has gained in interest (Fig. 27, (52)). HPLC separations are primarily carried out in the reversed phase mode however, for TLC separations normal phases are employed. Coupling of two highly efficient separation methods with each other brings about an increase in the information content of the analysis. 

Develop more energy-efficient separation methods such as extraction or reverse osmosis. 

Recent developments in SFC have not been inspired by any revolutionary new ideas. There has been progress in two directions in the area of SFC. One direction parallels the development of capillary GC, the second direction is similar to the development in HPLC. Because capillary SFC is a high efficiency separation method, it is most useful for the separation of complex mixtures. In combination with universal (FID) detection, it can be used as a fingerprint technique. 

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