Journal Pharmacy Research 2(9), 1542-1546 (2009) TLC on silica gel with n-hexane - ethyl acetate - glacial acetic acid 75:25:2. The hRf value was 38. Densitometric evaluation at 225 nm. The method was linear over a concentration range of 100-350 ng/band. The average recovery was 100.2 %. The samples were subjected to different stress conditions (acid, base, oxidative, heat) and all the degradation products were well resolved from the main compound. The method is suitable for stability studies and routine quality control.

Rasayan J. Chem. 2(3), 720-723 (2009). HPTLC of cefetamet on silica gel with toluene - chloroform - methanol 3:6:1. The hRf value of cefetamet was 35. Densitometric evaluation at 236 nm. The method was linear in the range of 1-5 µg/band. The recovery was 99.3-101.5 %. The method was found suitable for routine quality control.

62nd Indian Pharmaceutical Congress Abstract No. F-259 (2010). Health drinks usually contain several phytopharmaceuticals with immunomodulatory and antioxidant activities. TLC of gallic acid on silica gel with toluene – ethyl acetate – methanol – formic acid 15:15:1:4. The gallic acid content was established and the identity of the gallic acid zone in sample and standard was confirmed by UV spectra comparison.

J. Chem. Pharm Res. 2(5), 92-96 (2010). TLC of ofloxacin and cefixime on silica gel with methanol - ethyl acetate - 25 % ammonia 7:7:3. The hRf value of ofloxacin was 61 and of cefixime 78. The method was linear in the range of 50-500 ng/band. The recovery was in the range of 99.3-102.2 %. Quantitative determination by densitometry in absorbance mode at 295 nm.

J. Planar Chromatogr. 25, 320-325 (2012). HPTLC of ursolic acid in the leaves of Diospyros melanoxylon on silica gel with chloroform - methanol 19:1. Detection by dipping in 5 % methanolic sulphuric acid reagent and heating at 105 °C for 3 min. Quantitative determination by absorbance measurement at 540 nm. Linearity was in the range of 50-450 ng/zone for ursolic acid. Limits of detection and quantification were found to be 20 and 40 ng/zone. Recovery (by standard addition) was 97.5 %.

J. Planar Chromatogr. 29, 247-255 (2016). HPTLC of salicylic acid and their derivatives (acetylsalicylic acid, salicylanilide, salicylaldehyde, salicylamide, methyl salicylate, phenyl salicylate, 2,5-dihydroxybenzoic acid, salicylhydroxamic acid, 3,5-dinitrosalicylic acid, 3-aminosalicylic acid, 4-aminosalicylic acid, and 5-aminosalicylic acid) on silica gel with n-hexane – diethyl ether – 80 % acetic acid in various volume compositions (80:20:3, 60:20:3, 70:20:3, 80:10:3, 70:10:3, 60:10:3, 8:2:1, 7:2:1, 6:2:1, 8:2:2, and 8:2:3) and on RP-18, RP-8, and CN phase with methanol – water in various volume compositions (10:0, 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8). The best separation was obtained on RP-18W. Evaluation by cluster analysis (single linkage method, Euclidean distance).

(Chinese). (Determination of sorbic acid and benzoic acid in foods). TLC of sorbic acid and benzoic acid on polyacrylamide gel with butanol - NH3 - ethanol 7:1:2, or isopropanol - NH3 - ethanol 7:1:2. Detection by staining with 0.04 % bromocresol purple in ethanol. Sensitivity for both 3000 ng.

J. Chromatogr. 366, 396-4 02 (1986). TLC of 26 allo bile acids as their methyl esters on silica with hexane - ethyl acetate 83:17 and 3:2, and on C-18 silica with methanol - acetonitrile - water - formic acid 47.5:47.5:5:0.5 and 40:40:20:0.5. Also reversed-phase HPLC. The combined use of normal- phase and reversed-phase TLC appears helpful as a supplementary analysis to reversed- phase HPLC.