Planar chromatography automation

Two-dimensional separations in planar chromatography are rather trivial to perform. All unidimensional multiple development techniques employ successive repeated development of the layer in the same direction, with removal of the mobile phase between developments. The main variants are multiple chromatography and incremental multiple development. The basis for automated multiple development (AMD) is the automation of unidimensional, incremental, multiple development with a reverse solvent strength gradient [998]. 2D TLC finds limited use, and is mainly a qualitative technique. 

Technological progress has enabled automation of planar chromatography and will provide users with a greatly improved technique. Sueh improvements will now meet requirements of the industrial seetor, not only in terms of productivity, effectiveness, redueed... 

Thin layer chromatography (TLC), also known as planar chromatography, is an invaluable method used in chemistry and biochemistry, complementary to HPLC while having its own specificity. Although these two methods are applied differently, the principle of separation and the nature of the phases remain the same. Cheap and sensitive, this technique that is simple to use, can be automated. It has become essential principally since it is possible to undertake several separations in parallel. The development of automatic applicators and densitometers have led to nano-TLC, also called HPTLC, a highly sensitive technique which can be hyphenated with mass spectrometry. 

A technique that can achieve the maximum attainable resolution in TLC on a given separation distance without forced flow is automated multiple development (AMD). This step-gradient technique was developed by Burger. With respect to peak capacity the technique can be compared to HPLC, but it still maintains all benefits of planar chromatography. The heart of the instrument is a specially designed vacuum-tight chamber. Following sample application... 

Postaire, E.P.R. Delvordre, P. Sarbach, C. Automation and robotics in planar chromatography. In Handbook oflMn-Layer Chromatography 2nd Ed. Sherma, J., Fried, B., Eds. Marcel Dekker, Inc. New York, 373-385. 

Luftmann,H.,Aranda,M.,Morlock,G. (2007) Automated interface for hyphenation of planar chromatography with mass spectrometry. Rapid Communications in Mass Spectrometry RCM, 21, yill-TTIKi. 

Trypsteen MEM, Van Severen RGE, De Spiegeleer BMJ (1989) Planar chromatography of Echinacea species extracts with automated multiple development. Analyst 114 1021-1024... 

Delvorde, P., and Postaire, E. (1995). Automation and robotics in planar chromatography. 

The application of automation and robotics in planar chromatography has been discussed in a number of recent publications (Delvorde and Postaire, 1993 Post-aire et al., 1996 Buhlmann et al., 1994 Zieloff, 1995). Although various stages of the TLC process, such as multiple development, have been successfully automated, completely automated systems are not readily available. 

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