International Journal of Medical Toxicology & Legal Medicine 15 (1&2), 61-63 (2012). HPTLC for five benzodiazepines (alprazolam, clonazepam, diazepam, lorazepam and nitrazepam) on silica gel G with chloroform - acetic acid 9:1 in a presaturated TLC chamber. Detection by evaporisation with chlorine gas for 5 min, and after complete removal of chlorine, by spraying with o-tolidine reagent. Stabilisation of blue colored zones for a day by spraying the plate with 1 % phosphomolybdic acid. LOD for alprazolam, clonazepam, diazepan, lorazepam and nitrazepam was found to be 0.1, 0.5, 0.5, 1 and 0.5 µg/zone, respectively.

J. Liq. Chromatogr. Relat. Technol. 36, 2395-2404 (2013). HPTLC of carbidopa (1) and levodopa (2) in tablets on RP-18 with citrate buffer (pH 3.0) - methanol - formic acid 96:4:5. Detection by spraying with 0.02 % 2,2-diphenyl-1-picrylhydrazyl solution in ethanol (DPPH radical reagent). The hRf values of compounds (1) and (2) were 39 and 63, respectively. Linearity was in the range of 50-300 ng/zone for both (1) and (2). Intermediate precision was below 3.7 %. LOD and LOQ were 20.5-60.7 ng/zone for (1) and 27.8-61.1 ng/zone for (2), respectively. Recovery (by standard addition) was 99.6-95.4 % for both.

J. Planar Chromatogr. 26, 202-208 (2013). HPTLC of egg yolk lipid fractions on silica gel with hexane - diethyl ether - formic acid 40:10:1. Detection by srpaying with 10 % copper(II) sulfate in 8 % phosphoric acid. Quantitation by scanning with a flatbed scanner and a gel analysis software. Intermediate/interday/intra-day precision was below 10 % CV (n=6).

J. Planar Chromatogr. 26, 306-311 (2013). HPTLC of baicalein (1), hispidulin (2), chrysin (3), and oroxylin A (4) in different plant parts of Oroxylum indicum on silica gel with chloroform - methanol 97:3 + 1 drop water + 1 drop formic acid. Quantitation by absorbance measurement at 270 nm. The hRf values for compounds (1) to (4) were 22, 2, 36 and 61, respectively. Linearity was in the range of 500-2500 ng/zone for (1) to (4). LOD and LOQ were 77 and 257 ng/zone for (1), 99 and 330 ng/zone for (2), 69 and 229 ng/zone for (3) and 45 and 151 ng/zone for (4), respectively. Average recoveries were 98.3 % for (1), 95.2 % for (2), 100.2 % for (3) and 98.0 % for (4). Intermediate/interday/intra-day precision was below 5 % (n=5).

species by validated HPTLC–densitometric method. J. Planar Chromatogr. 26, 248-253 (2013). HPTLC of ardisicrispin A in the roots, stems, leaves, fruits and flowers of Lysimachia nemorum L. (1), Lysimachia nummularia L. (2), Lysimachia vulgaris L. (3), Lysimachia punctata L. (4), Lysimachia thyrsiflora L. (5), Lysimachia ephemerum L. (6), Lysimachia ciliata L. (7), and Lysimachia clethroides Duby (8) on silica gel with chloroform - methanol - water 8:7:1 for (1), (3) and (7) and n-butanol - acetic acid - water 6:1:3 for (2), (4), (5), (6) and (8). Detection by spraying with 25 % sulfuric acid in methanol, followed by heating at 105 ºC for 5 min. Quantitative determination by absorbance measurement at 545 nm. The hRf values for ardisicrispin A in both development systems were 86 and 36, respectively. Linearity was in the range of 2-13 µg/zone. LOD and LOQ were 620 and 950 ng/zone for the chloroform mobile phase and 1890-2880 ng/zone for the n-butanol mobile phase. Average recovery was in the range of 94.3-95.1 %. Intermediate/interday/intra-day precision was below 4 % (n=3).

J. Planar Chromatogr. 26, 56-61 (2013). TLC of ofloxacin (1) and dexamethasone (2) on silica gel with methanol - 0.01 M phosphate buffer 2:3 and pH adjusted to 5 with orthophosphoric acid. Quantitative determination by absorbance measurement at 300 nm for (1) and 240 nm for (2). The hRf values for (1) and (2) were 22 and 60, respectively. Linearity was in the range of 1-6 µg/zone for both (1) and (2). The LOD and LOQ were 260 and 870 ng/zone for (1) and 220 and 740 ng/zone for (2), respectively. Average recovery (by standard addition) for (1) and (2) was 99.2 %. Intermediate/interday/intra-day precision was below 2 % (n=3). The method showed comparable results with a validated HPLC method.

J. Planar Chromatogr. 26, 254-259 (2013). HPTLC of ursolic acid (1), betulinic acid (2), beta-sitosterol (3), and lupeol (4) in the stem bark, root bark and leaves of Alstonia scholaris on silica gel with chloroform - methanol 99:1. Detection by dipping into vanillin-sulfuric acid reagent for 2 s, followed by heating at 96 ºC for 8 min. Quantitative determination by absorbance measurement at 680 nm. The hRf values for (1) to (4) were 18, 27, 57 and 77, respectively. Linearity was in the range of 2-10 µg/zone for (1) and 84) and 4-20 µg/zone for (2) and (3). LOD and LOQ were 330 and 1100 ng/zone for (1), 530 and 1310 ng/zone (2), 290 and 970 ng/zone for (3) and 340 and 1140 ng/zone for (4), respectively. Average recoveries (by standard addition) for (1) to (4) were between 98.9 and 100.5 %. Intermediate/interday/intra-day precision was below 2 % (n=9).

J. Liq. Chromatogr. Relat. Technol. 37, 2021-2035 (2014). HPTLC of thirteen 5-arylidene-2,4-thiazolidinediones on RP-18 with one of six organic solvents: acetonitrile (with increasing acetonitrile content from 55% to 75%), methanol (60–90%), ethanol (40–70%), propanol (35–55%), acetone (55–75%), and dioxane (50–70%) with each modifier in increasing steps of 5%. A quantitative structure-retention relationship study allowed to investigate the retention behavior of these substances.