J. AOAC Int. 93, 792-797 (2010). HPTLC of alprenolol on silica gel with methanol - 25 % ammonia 99:1 in a chamber saturated for 10 min. Quantitative determination by absorbance measurement at 270 nm. The linearity range was between 1.03 and 20.6 µg/zone. The %RSD of precision was 3.9 %. The recovery of alprenolol was at 80 % level 100.1 % with a %RSD of 2.2 %, at 100 % level 99.9 % with a %RSD of 3.9 %, and at 120 % level 104.4 % with a %RSD of 2.9 %. The LOD was 520 ng/zone and LOQ 1550 ng/zone.

J. Planar Chromatogr. 24, 105-107 (2011). TLC of twelve bisquaternary acetylcholinesterase reactivator HI-6-salts (sulfate, chloride, acetate, bromide, phosphate, mesylate, tartrate, iodide, malonate, salicylate, maleinate, and tosylate) on cellulose with acetone - acetic acid - water - toluene 5:2:2:1, butanol - acetic acid - water - toluene 1:1:1:1, isopropanol - acetic acid - water - toluene 5:2:2:1, and isopropanol - formic acid - water - toluene 6:2:2:1 in a twin-trough chamber. Detection under UV light at 254 nm and by spraying with Dragendorff’s reagent.

J. Ethnopharmacol. 137, 1337-1344 (2011). HPTLC of phyllanthin (A) and gallic acid (B) in the whole plant of Phyllanthus simplex on silica gel with hexane - ethyl acetate 5:1 for (A) and ethyl acetate - formic acid 44:3 for (B). Detection by spraying with anisaldehyde - sulfuric acid reagent. Quantitative determination by absorbance measurement at 260 and 520 nm. The hRf values of (A) and (B) were 19 and 82, respectively. The amount found in samples was 14.5 % for (A) and 0.7 % for (B).

J. Planar Chromatogr. 24, 373-375 (2011). HPTLC of red clover capsule extracts and formononetin, biochanin A, daidzein, glycitein, and genistein on silica gel, prewashed with methanol, with dichloromethane - glacial acetic acid - ethyl acetate 12:2:1 in a horizontal chamber saturated for 15 min. Quantitative determination by densitometry at 260 nm. The hRf value was 29, 34, 41, 48, and 59 for daidzein, glycitein, genistein, formononetin, and biochanin A, respectively. The two major isoflavones are formononetin and biochanin A. The limit of detection and quantification was 14 and 47 ng/band for formononetin and 12 and 40 ng per band for biochanin A, respectively. The recovery was 93.3-100.7 % for formononetin and 102.0-109.4 % for biochanin A.

J. AOAC Int. 94, 1094-1099 (2011). TLC of caffeine and paracetamol in capsules and tablets on silica gel with n-hexane - ethyl acetate - ethanol 25:15:4. Detection at 254 nm. Quantitative determination by densitometry at 254 and 270 nm. The hRf value of caffeine and paracetamol was 48 and 73, respectively. Linearity was between 0.2-1.9 for caffeine and 0.03-1.5 µg/L for paracetamol. The detection limit of caffeine was 25 ng/L and of paracetamol 32 ng/L. The precision was 1.9 % (n=6). Recovery (by standard addition) was 98-99.5 % for both compounds.

E-Journal of Chemistry 7(51), 5559-5565 (2010). TLC of sucralose in commercially available tabletop sweeteners, dietetic sweets and soft drinks on silica gel with chloroform - methanol - toluene 10:7:3 (system 1) and chloroform - ethanol - benzene 5:3:2 (system 2). The hRf value of sucralose was 62 with system 1 and 45 with system 2. Detection by dipping in rhodamine-sulphuric acid reagent, followed by heating at 120 °C for 3 min. The band corresponding to sucralose appears as olive-green band with ?max at 456 nm. The fluorescence property of the sucralose derivative can be used for quantitative analysis (?max 366 nm). The method is highly reproducible as other carbohydrates and artificial sweeteners don’t produce a fluorescent olive-green color with this reagent. The method was applied to cola drinks, lemon juices, sugar free sweets, and tabletop sweeteners with excellent results. The LOD was 5-7 ng/band and linearity was in the range of 40-250 ng/band for both methods.

J. Planar Chromatogr. 23, 365-368 (2010). HPTLC of palmitoyl hexapeptide (an antiwrinkle peptide) on silica gel with toluene - ethanol 9:1 in a twin-trough chamber with saturation for 30 min at room temperature (25 +/- 2 °C). The hRf was 33. Quantitative determination by absorbance measurement at 211 nm. Linearity was between 10 and 30 ng/band. The LOD and LOQ was 3 and 9 ng/band, respectively. The intra-day precision (%RSD, n = 6) was 0.9-1.5 % and the inter-day precision 0.9-1.4 %. The small %RSD obtained after small changes of the method conditions indicate the method is robust. The recovery of the method was in the range of 98.9-101.3 %.

J. Planar Chromatogr. 24, 306-311 (2011). HPTLC of ethanolic leaf extracts of A. squamosa, with rutin and isoquercitrin as standards, on silica gel (prewashed with methanol) with ethyl acetate - formic acid - glacial acetic acid - ethyl methyl ketone - water 50:7:3:30:10 with chamber saturation for 30 min at room temperature (25 +/- 2°C) and a relative humidity of 50 +/- 5 %. Quantitative determination by densitometry at 366 nm. Linearity was between 200-1600 ng/band for both rutin and isoquercitrin. The robustness of the method (%RSD) was 1.9-2.9 % for rutin and 1.5-2.3 % for isoquercitrin, respectively. The instrumental precision (%RSD) was 0.9 and 0.3 % for rutin and isoquercitrin, respectively. The intra-day and inter-day precision (%RSD) was less than 3 % in all cases. LOD and LOQ was 75 and 100 ng/band for rutin and 40 and 80 ng/band for isoquercitrin, respectively. The hRf value was 32 for rutin and 58 for isoquercitrin. Recovery (by standard addition) was found to be 96-107 %.