Chromatogr. Sci. 52, 313-434 (1990). A review with 13 references on the continuous development in TLC for the separation of complex mixtures.

J. Planar Chromatogr. 3, 121-125 (1990). Demonstration of the variability of the external pressure in OPLC technique. In fully off-line OPLC for single development, increasing external pressure yields a more efficient separation, high peak capacity, and increased sensitivity, whereas, under conditions reported, on-line OPLC does not provide the same efficiency increase.

J. Planar Chromatogr. 5, 308-315 (1992). Summary of advantages and disadvantages of normal (N) and sandwich (S) chambers including OPLC chambers; report of the possibilities of transferring optimized TLC mobile phases to different planar chromatographic methods in fully off-line modes.

Chromatography with aqueous solutions of carbohydrates as eluents. J. Chromatogr. 695, 160-164 (1995). Investigation of the effect of adding carbohydrates to the aqueous eluent in adsorption TLC on cellulose. Discussion of the Rf changes when sucrose or linear dextrans, soluble starch were added to the eluent.

Proc. 9th Internat. Symp. Instr. Chromatogr., Interlaken, April 9.-11., 95-102 (1997). Overpressured layer chromatography (OPLC) can be performed as fully off-line and fully on-line, even in partition or combined techniques; variations which offer new possibilities to select the most effective technique for a given analytical or preparative task. Fully off-line OPLC is first of all an analytical method, while fully on-line and off-line/on-line OPLC are more appropriate applied for preparative purpose. HPTLC of furocumarin isomers and opium alkaloids on silica with multicomponent solvents, methyl ethyl ketone - chloroform - ether - n-hexane 128:18:27:827 for the separation of furocumarin isomers and hexane - ethyl acetate - acetone - dichloromethane - methanol - diethyl amine 200:300:300:50:27:31 in a saturated chamber and 80:60:60:10:5:6 in an OPLC chamber for opium alkaloids. Quantification by densitometry at 313 nm for furocumarin isomers and at 280 nm for opium alkaloids.

J. Chromatogr. A 903 (1/2), 211-217 (2000). Use of planar chromatography with electroosmotic flow to separate either a mixture of dyes using 80% ethanol or a mixture of miscellaneous compounds using 45% aqueous acetonitrile as mobile phase. Both mobile phases are 1.0 mM in N-[tris(hydroxymethyl)]-3-aminopropanesulfonic acid (TAPS) buffer. Presentation of the respective relationship between migration velocity and applied potential and between analysis time and distance migrated. Discussion of the merits compared to conventional TLC.

Proc. Intern. Symp. on Planar Separations Plan. Chrom. 89-109 (2003). The velocity and migration distance of the mobile-phase front in porous media, in normal TLC practice controlled by capillary forces, can be increased by application of an external electric field. The effect is observed on different TLC plates developed with non-polar and polar solvents. As a result the separation resolution of some compounds was improved. The method, a hybrid of electric forced flow and classical TLC, was named "planar dielectrochromatography" (PDEC).

J. Planar Chromatogr. 17, 411-419 (2004). A new concept, the flowing eluent walls (FEW) process, for segmentation of a non-segmented adsorbent bed, has been used for single- and multi-channel on-line overpressured-layer chromatography, which leads to active and non-active regions on the adsorbent layer during the separation process. Mobile phase only is introduced to the non-active part of the layer whereas mobile phase and sample can be admitted to the active parts. The FEW concept provides the possibility of real multichannel liquid chromatographic separation on a non-segmented layer and column shaped adsorbent bed. Separation of chamomille oil, dye mixtures, ascorbigen standards, and cabbage extracts, were used as examples. The FEW configuration is suitable for rapid isolation of relatively large amounts of a substance.