The New Technology Of Thin-layer Chromatography And Its Application In The Analysis Of Traditional Chinese Medicine

A new distributor, which can be used on half-way development more perfectly, is described in this paper. The distributor is made of two slides, with carefully polishing and gluing together like a funnel. The mobile phase can be supplied into the new distributor by syringe, the solution will full of the capillary crack immediately and then leak to the thin layer plate, development can begin at the same starting line. Compared with old device, the new device can supply lowest even distance, is more suitable for retreating two closed spots.An improved method of two-dimensional development in thin-layer chromatography is described in this paper. The innovative feature is that before the second development the thin layer on the glass plate is divided into several zones and this zones are developed with different mobile phases, instead of with the same mobile phase, as in traditional two-dimensional TLC. The operating procedure and the device are described in detail, as are means of avoiding interference.A new mobile phase optimization method- Rf index method by external standard is developed. Seven kinds frequently used solvents are arrayed to 16 kinds duality mobile phases. Every duality mobile phase has three different levels of composition. The index table is made up of 48 kinds of mobile phases and the Rf values which eight dyes were developed with all kinds of mobile phases. After application of sample and eight dyes at a plate, the plate is developed with arbitrary mobile phase (Not all Rf value can be 0 or 1). According to correspondencerelationship between spots of sample and dyes, we can find a suitable mobile phase from index table, by which the disseparated spots would be pushed into a new zone with suitable Rf value by Half-Way development. This is a very simple and effective method for selecting mobile phase, especially for half-way development.A new development mode of TLC, multidimensional relay development, which is developed on the basis of half-way development and relay development, is described in this paper. The new method provides wider space to further separate spots and suits to no-color sample. By the multidimensional relay development using the device of half-way development some disseparated spots are transferred to some new thin layer plate on the basis of the first separation, then these new plate are redeveloped. The process is very simple and effective. If transfer rate are high enough, it would make a great improvement to the TLC separation result.The mixtures of dyes and extracts of traditional Chinese drug were used to evaluate the technique and the results obtained were satisfactory.