Acta Pharmaceutica Hungarica 59, 167-172 (1989). TLC of 2ß,16ß-bis-(4'-dimethyl-1‘piperazino)-3a,17ß-diacetoxy-5a-andro stane (=Arduan) on silica with chloroform - dichloromethane - methanol 6:2:2. NaI in an unsaturated development tank sealed airtight. Determination of radioactivity of the parent drug and metabolites separated by ion-pair TLC.

Dtsch. Apoth. Ztg. 139, 517-518 (1999). Approved procedure for identity and quality test TLC and HPTLC of betamethasone 17a-valerate (using prednisolone acetate, hydroxycortisone acetate or dexamethasone acetate as reference substances) on silica gel with ethyl methyl ketone - toluene 2:3; without chamber saturation, bandwise application. The plate is left in the air for 15 min after application. Detection under UV 254 nm, after spraying with ethanolic sulfuric acid solution and heating at 110°C, and under UV 360 nm.

J. Planar Chromatogr. 30, 136-141 (2017). 2D-HPTLC of estrone (1), estradiol (2), 17α-ethinylestradiol (3), estriol (4), bisphenol A (5), trans-resveratrol (6), zearalenone (7), and diethylstilbestrol (8) on RP-18W with hexane – ethyl acetate – acetone 11:3:2 in the first direction and acetone – water 3:2 in the second direction. Detection by heating at 110 °C for 10 min, followed by dipping into a mixture of sulfuric acid - water 1:49 for 1 s and heating again at 110 °C for 10 min. Quantitative determination under UV light at 366 nm. The hRf values in the first/second direction for (1) to (8) were 52/27, 36/27, 45/24, 6/44, 41/31, 51/17, 49/22 and 17/47, respectively. 17α-ethinylestradiol was quantified in an effect-directed analysis using the yeast strain S. cerevisiae BJ3505. The activation of the estrogen receptor by estrogen active compounds was measured by inducing the reporter gene lacZ which encodes the enzyme ß-galactosidase. The enzyme activity was determined directly on TLC plate by using the fluorescent substrate MUG (4-methylumbelliferyl ß-D-galactopyranoside). The LOD and LOQ were 31 and 57 pg/zone, respectively.

Acta Pharmaceutica Hungarica 63, 19-27 (1993). TLC of ethinylestradiol, mestranol, norgestrel, norethisterone on silica with toluene - ethyl acetate 2:1. Visualization by spraying with 1% cerium(IV)sulfate solution in 10 % aqueous sulfuric acid and heating at 110 °C for 5-10 min.

lanceolata with an energy audit (thermal × microwave × acoustic):_x000D_ a case study of HPTLC determination with additional specificity using on-line/off-line_x000D_ coupling with DAD/NIR/ESI-MS. Phytochem. Anal. 25, 551-560 (2014). HPTLC of (1)taraxasterol, (2) taraxasterol acetate and (3) stigmasterol in P. lanceolata on silica gel with hexane - ethyl acetate 22:3, detection by spraying with anisaldehyde sulphuric acid reagent, followed by air drying for 40 min. Quantitative determination by absorbance measurement at 645 nm. The hRF values of (1) to (3) were 75, 33 and 19. Linearity was in the range of 1-5 μg/zone for (1) to (3). The intermediate intra-day and inter-day precisions were below 2.3 % (n=3). The LOD and LOQ were 530 and 1760 ng/zone for (1), 240 and 790 ng/zone for (2) and 110 and 370 ng/zone for (3), respectively. Recoveries were in the range of 98-105 % for (1), 101-131 % for (2) and 95-116 % for (3).

J. Sep. Sci. 41, 518-524 (2018). HPTLC of withanolide S in the leaves of Withania somnifera on silica gel with dichloromethane – toluene – methanol – acetone 15:2:1:1. Detection by spraying with sulfuric acid reagent (180 mL methanol with 20 mL sulfuric acid) followed by heating at 120 °C for 10 min. Quantitative determination by fluorescence measurement at 365/>400 nm. The hRF value for withanolide S was 7. Linearity was between 15 and 500 μg/mL. LOD and LOQ were 30 and 92 μg/mL. The intermediate/interday/intra-day precisions were below 2 % (n=3). Recovery was in the range of 94.6 and 99.1 %.

Lipids 18, 87-89 (1983). The chromatographic mobilities of 17 sterols and squalene on reversed-phase TLC plates with 4 nonaqueous solvent systems is described. Solvent Systems: hexane - ethyl acetate 9:1 and other systems were used. Visualization: 10 % phosphomolybdic acid in 95 % ethanol, followed by heating at 100 °C; iodine vapor; 10 % sulfuric acid in 50 % methanol, followed by heating at 100 °C.

J. Chromatogr. 445, 385-392 (1988). TLC on silica with hexane - ethyl acetate - acetone 5:4:1. Immersion for 10-20 s in a fluorogenic reagent containing 100 mL ethanol, 100 mL ether and 4 mL concentrated sulfuric acid. Development in the 2nd direction with hexane - ethyl acetate - dichloromethane 1:2:2. Detection under UV 366 nm. Detection limit, 0.5 µg for both.