J. Planar Chromatogr. 20, 365-371(2007). Estimation of retention data by use of correlation equations and physicochemical properties is a useful tool in liquid chromatography. HPTLC of an homologous series of 9 s-triazines on RP-18, cyano-, and amino phase in unsaturated chambers with aqueous solutions of the organic solvents acetonitrile, tetrahydrofuran, and dioxane. After development the dried plates were examined under UV light at 254 nm.

62nd Indian Pharmaceutical Congress Abstract No. F-301 (2010). TLC of brimonidine tartrate on silica gel with methanol – toluene – triethylamine 10:35:2. The hRf value was 48. Quantitative determination by absorbance measurement at 247 nm. The method was linear in the range of 100-600 ng/band. The sample was subjected to different stress conditions (acid, base, oxidative, thermal and photolytic). With the proposed method all the degradation products were well resolved from the drug.

Der Pharma Chemica 2(3), 8-18 (2010). HPTLC of berberine on silica gel with methanol – acetic acid – water 8:1:1. The band corresponding to berberine showed an hRf value of 74. Quantitative determination by absorbance measurement at 350 nm. The method was linear in the range of 100-500 ng/band. Different samples analysed by the proposed method were found to contain 11.8-12.5 mg/g berberine. The recovery was between 98.0-100.3 %.

J. Liq. Chromatogr. Relat. Technol. 38, 1499-1506 (2015). RP-HPTLC of piperazine in pharmaceutical formulations on RP-18 with acetonitrile - water 3:2 modified with 1.5 % tetrafluoroborate. Quantitative determination by absorbance measurement at 247 nm. The hRF value for piperazine was 43. Linearity was in the range of 0.8-2.2 μg/zone. LOD and LOQ were 0.11 and 0.34 μg/zone. The intermediate precision was below 3.5 % (n=3). Recovery was between 99 and 103 %. Significant changes and improvements regarding the hRF value were observed when tetrafluoroborate was added to the mobile phase.

J.of Medicinal Chemistry 31, 650-656 (1988). TLC of polyoxins on silica with 1-butanol - acetic acid - water 4:1:2. Detection under UV or by spraying with ninhydrin in butanol.

Proc. 6th Int. Symp. Instrum. Planar Chromatogr., (Interlaken 1991), Inst. Chromatogr., Bad Dürkheim, FRG, 157-173 (1991). Determination of title substances on HPTLC-NH2 plates. Qualitative analysis in human urine and serum, 2-fold development with 1-propanol - nitromethane - water - glacial acetic acid 30:30:10:1. Detection under UV or by heating at 150°C. Quantitative analysis of uric acid, creatine, creatinine and glucose in human urine; two-fold development with 1) acetonitrile - water 70:30, 2) ethyl acetate - pyridine - water - acetic acid - propionic acid 50:50:10:5:5. Quantitative analysis of glucose, creatinine and uric acid in serum; two-fold development in 1) acetonitrile - water 80:20, 2) ethyl acetate - pyridine - water - glacial acetic acid - propionic acid 50:50:10:5:5. Quantitative determination by fluorescence 366/>400 nm.

J. Planar Chromatogr. 7, 399-405 (1994). Investigation of retention of azines and diazines in RP-TLC with RP-2, RP-8 and RP-18 material and methanol - water eluents; the practical usefulness of the retention model employed was established for pyrazine, quinoxaline, pyridine, quinoline, c-picoline, 2-methylquinoxaline, for their dehydrocondensation products, and for their sulfur derivatives. Visualization with Dragendorff's reagent, followed by additional spraying with sulfuric acid.

III. TLC on silica of 2,3,4-trisubstituted tetrahydroisoquinolinones. J. Liq. Chromatogr. & Rel. Technol. 26, 1255-1266 (2003). Application of LSChrom software TLC of 12 tetrahydroisoquinolinones on silica gel with 7 different mobile phases, e.g. heptane - ethyl acetate 56.7:43.3, heptane acetone 73.7:26.3, heptane - isopropanol 83.4:16.6 and toluene - acetonitrile 83.3:16.7. The automatic selection of the mobile phases is based on the structure of any compound, literature data for the adsorption properties of the relevant structural fragments (groups) available in the structure and a many calculations.