Marking of the Layer

To evaluate the chromatogram, the template is placed again in the second position and the JS/-values can be read off directly for a length of run of 10 cm. The approximate sizes of circular spots can be rapidly and semi-quantitatively estimated by comparison with the variously sized circles on the template. 

The mixture is brought into solution and applied to the start (starting point or line) as a spot or band respectively. 

Most solutions for application are between 0.1 and 1%. From 1 to 20 mm is normally applied.  

The start points should be equally sized as far as possible and have a diameter between 2 and, at the most 5 mm. 

The application of standard solutions and pre-determined volumes is strongly recommended, even in so-called qualitative chromatography. Various measuring devices can be used for this purpose, like those illustrated in Fig. 20. 

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