Separation parameters, fine-tuning

This chapter illustrates the improvements in SEC column technology and modern applications of SEC separations. The better understanding of SEC column design and separation parameters described in the theoretical sections of this chapter will help the reader fine-tune his or her own work. The same is true for column performance tests, which should be applied regularly, especially after a column purchase. In order to obtain reproducible results, it is recommended to choose column manufacturers who can assure constant quality and performance and to invest in knowledgeable, well-trained support personnel and experienced application chemists. 

Mesostructured materials with adjustable porous networks have shown a considerable potential in heterogeneous catalysis, separation processes and novel applications in optics and electronics [1], The pore diameter (typically from 2 to 30 nm), the wall thickness and the network topology (2D hexagonal or 3D cubic symmetry) are the major parameters that will dictate the range of possible applications. Therefore, detailed information about the formation mechanism of these mesostructured phases is required to achieve a fine-tuning of the structural characteristics of the final porous samples. 

With respect to conversion, selectivity, and operation, the oxo synthesis is influenced by a plethora of parameters. By fine-tuning of the operation conditions, a broad band of product compositions is achievable. In accordance with the mechanistic discussion and the kinetics of the hydroformylation reaction, these issues will be treated separately for unmodified and modified catalysts. For operating processes and their reaction parameters, see Section 2.1.1.4. 

At this stage, any co-elution of the key analytes is corrected by fine-tuning the separation parameters, mostly by adjusting selectivity (a) (see Figure 2.17). This process may be quite challenging and iterative for multi-component assays of complex samples. Afterwards, efforts are focused on improving other method performance measurements such as sensitivity, peak shape, robust-... 

While EOF is beneficial and is exploited in CE it must be controlled since if it is too high the analyte species will have migrated to the cathode before separation has occurred. The EOF can be fine tuned by adjusting the following parameters. 

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