Figure 19 Now we test with brush 5 or 6 clean mobile phases. The brush point is positioned about 1..2 mm below the sharpened sample line, The mobile phase numbers are HALPAAP numbers for Silica plates. Click on 19 and then in the TLC/HPTLC pictogram page on 19 again. Figure 19 shows, that phase no. 2 - hexane - moves no one substance, mobile phase 23 would be useful only if the red substances must be quantitized: Most promising is mobile phase 9. A similar concept but more time consuming is an old procedure seen under TLC HPTLC pictograms no. 20. Click HEREand when switched to the TLC part of this book click on 20.