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Tobias Revermann (promotion date: 2 February 2007)

Methods and instrumentation for quantitative microchip capillary electrophoresis

Promotion date: 2 February 2007


The development of novel instrumentation and analytical methodology for quantitative microchip capillary electrophoresis (MCE) is described in this thesis. Demanding only small quantities of reagents and samples, microfluidic instrumentation is highly advantageous. Fast separations at high voltages have been performed, which require the use of flexible high-voltage power supplies that have been developed in this work.

What is your thesis about?

As the thesis title says I developed methods and instrumentation for microchip capillary electrophoresis. This is a chipbased technique for the separation of different substances by applying a high voltage, which causes the analytes to migrate from one end of the channel to the other. Depending on their properties they do this at a different speed. At the end of the channel the separated analytes pass a detection system and can be analyzed quantitatively.

As far as I know the procedure of electrophoresis is not new.

That’s right. The focus of my research was not on the development of some new kind of chip, but on the quantitative element. I used existing chips for this quantitative analysis, determining the exact quantity of a chemical in a sample. The amount of thiol in depilatory cream for instance.

The advantage for the user is that you can use only small amounts of sample. Also the method requires less reagent producing less chemical waste and it is usually much faster than existing methods.

Is your method ready to be applied in industry?

Usually industry is slow to adapt. Only when they start a new line of development they look into new techniques. Once a production environment is well established they stick to the old methods.

But surely, if money can be saved??

True. But this work is but one step in the direction. Perhaps in 5 years. Now a degree of automation is still lacking; a lot of steps in the process have to be taken manually. A new PHD research is needed for actual commercialization.

But still, your research is a big step forward?

Yes. But it took some doing to get it right. We had some technical problems to control the microfluidics on the chip, requiring high voltage supplies. The available commercial instruments in this field all presented small problems. So I started to develop my own high voltage power supply together with an electrical engineer.

That is why the instrumentation is also a part of my thesis.

But I was lucky that I could work together with the electrical engineer.

From this university?

From Münster actually. Because my promoter, Professor Uwe Karst, moved there.

What did you enjoy most in doing a PhD?

It offered me a possibility to do my own piece of research. I had a very good working relation with my supervisor and colleagues. Alone I would never have come up with the right ideas.

What are your plans?

I already have got a job. I am working at a German paint company located close to Frankfurt, doing chemical analysis on indoor air.

For the summary of the thesis, click here. (PDF)