Microreactors integrated system

Richter, T, Eheeeld, W., Gebauee, K., Golbig, K., Hessel, V., Lowe, H., Wole, A., Metallic microreactors components and integrated systems, in Eheeeld, W., Rinaed, 1. H., Wegeng, R. S. (Eds.), Process Miniaturization 2nd International Conference on Microreaction Technology, IMRET 2, Topical Conf Preprints, pp. 146-151, AlGliE, New Orleans (1998). 

Flexible tubes with a 2.4-mm id were connected to each side of the microreactor as sampling lines of the integrated FIA system. In this new biosensor integrated FIA system, HRP was still used in solution with the other two reagents and injected into the FIA line after the sample reacted with the immobilized AOD. Figure 3 shows the new integrated system. 

If microreactors, either as components or integrated systems, will run in parallel as an array, new solutions for feeding or dispensing systems have to be developed. This is also true for the process control of a large number of product streams which will be a challenge for realization. Tomorrow s answers to these questions will determine which type of microreactor will be favored and will specify the major applications, either simulation of processes, synthetic production or mass screening. 

Silicon is undoubtedly the material which has been most often applied for microfluidic applications, especially in the field of analysis systems. Detailed information has also been obtained for a number of microreactor components and some of them are already commercially available. Even more striking, first experiments with integrated systems have been reported by DuPont [8]. However, silicon components did not find a broad use in industrial applications, especially in the field of synthetic chemistry. For this purpose, future developments have to address a broader variety of components than those mentioned above, including e.g. heat exchangers, extractors and others, and the feasibility of the fabrication of integrated systems has to be demonstrated in more detail. 

Figure 11.3 Photograph of the microreactor integrated in a standard MALDI-TOF sample plate. Because of the self-activating character of the microfluidics device, the system can be introduced into the MALDI ionization chamber without any wire or tube for the feeding and flow control.

The detection range of 0.05 to 1.5 g ethanol/1, obtained with the system FIA-I, working with only one microreactor, was changed to 0.001 to 0.066 g ethanol/1 when a second microreactor was introduced in the FIA-I line, packed with the immobilized HRP (integrated system II), to reuse both enzymes in successive analysis. That instrument permitted the analysis of low ethanol contents, in highly diluted solutions. The analysis cost will decrease once the immobilized enzymes could be reused, in successive measurements, always using the same immobilized lot. On the other hand, the enzymes lose the activity when they are reused in successive analyses [4]. 

Miniaturized chemical analysis systems have been developed for most macroscopic counterparts (Dittrich et al. 2006). The availability of optical fibers, light sources, and detectors in the visible UV and near-infrared (NIR) wavelengths makes it possible to integrate spectroscopic measurements in microreactors (Lobbecke et al. 2005). Fourier transform infrared spectroscopy (FTIR) is an efficient, broadly applicable... 

Mensinger, H., Richter, T., Hessel, V., Dopper, J., Ehrfeld, W., Microreactor with integrated static mixer and analysis system, in van den Berg, A., Bergfeld, P. (Eds.), Micro Total Analysis Systems, Kluwer, Dordrecht, 1995, 237-243. 

Fig. 3. Proposed integrated FIA system, with microreactor packed with immobilized AOD 1, buffer solution 2, sample solution 3, horseradish peroxidase and reagents solution 4, eight-channel distribution valve 5, coil 6, peristaltic pump 7, colorimeter 8, computer 9, micro reactor 10, eight-channel injection valve 11, waste.

Microreactor technology has developed to such an extent that a wide variety of microreactor components, e.g. micropumps, mixers, reaction chambers, heat exchangers, separators and complete integrated microreaction systems with process control units have been fabricated using the appropriate microfabrication process and materials that are suitable for specific applications. 

Mensinger H, Richter Th, Hessel V, Dopper J, Ehrfeld W (1995) Microreactor with integrated static mixer and analysis system. In Micro Total Analysis Systems, van den Berg A, Bergveld P (eds) Kluwer Academic Publishers, The Netherlands, p 237... 

Edelmann FT (1996) Rare Earth Complexes with Heteroallylic Ligands. 179 113 -148 Edelmann FT (1996) Lanthanide Metallocenes in Homogeneous Catalysis. 179 247-276 Effenhauser CS (1998) Integrated Chip-Based Microcolumn Separation Systems. 194 51 - 82 Ehrfeld W, Hessel V, Lehr H (1998) Microreactors for Chemical Synthesis and Biotechnology -Current Developments and Future Applications. 194 233 - 252 Ekhart CW, see de Raadt A (1997) 187 157-186... 

Microfluidic concepts can be used to develop an integrated total chemical analysis system (TAS) [40], which include sample preparation, separation, and detection. The microminiaturization of a TAS onto a monolithic structure produces a //-TAS that resembles a small sensor. The first /(-TAS was a micro-gas chromatograph (GC) fabricated on a 5-in. silicon wafer in 1979 by a group at Stanford University [41]. Since then, developments in micromachining has led to the development of microsensors, microreactors,... 

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