J. Planar Chromatogr. 24, 214-217 (2011). HPTLC of six phenolic compounds (phenol, 2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, and pentachlorophenol) in water samples extracted using microliter volumes of 1-undecanolon, on RP-18 with methanol - water 2:1 in a twin-trough chamber. Detection by spraying with a mixture of iron(III) chloride and potassium ferricyanide. Quantitative determination by densitometry in absorbance mode at 254 and 725 nm. The calibration curves were linear in the range of 0.025-4.0 and 0.1-20.0 mg/band. The limits of detection and quantification were between 8-35 and 25-98 ng/band, respectively. The relative standard deviation for repeatability was between 2.6 % and 6.4 %. Recovery (by standard addition) was between 89.2-101.7 %.

J. Planar Chromatogr. 24, 412-418 (2011). HPTLC of milnacipran hydrochloride on silica gel, prewashed with methanol, with chloroform - methanol - ammonia 64:25:2 in a twin-trough chamber saturated for 20 min. Detection under UV light at 245 and 366 nm. Quantitative determination by absorbance measurement at 220 nm. The hRf value of milnacipran was 45. Linearity was between 500 and 6000 ng/zone. The method precision, intra-day precision, inter-day precision, and different analyst precision (n = 6 each, %RSD), was 1.2, 1.9, 1.6, and 1.9 %, respectively. The mean recovery (n = 3) was 99.2-99.8 % with a % RSD between 0.6-1.7 %.

and Gentianella acuta by thin-layer chromatography) (Chinese). J. of Inner Mongolia Univ. for Nationalities (Natural Sci. Edit.) 26(1), 71-72 (2011). TLC of the extracts of the title medicinal herbs on silica gel with 1) chloroform - methanol - water - formic acid 28:2:2:1, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 °C until the zones were detected; 2) chloroform - methanol - ammonia 40:10:1, detection by spraying with iodine solution. Identification by comparison of the fingerprint with the main components gentianine, isoorientin, flavone, isobellidifolin, swerchirin, and 1,5,8-trihydroxy-3,4-dimethoxyxanthone.

J. Liq. Chromatogr. Relat. Technol. 34, 2548-2464 (2011). HPTLC of tocopherol acetate (1) and tocopherol (2) in oral fluid vitamin E on silica gel with chloroform - cyclohexane 11:9. Quantitative determination by absorbance measurement at 202 nm for (1) and 272 nm for (2). The hRf values of (1) and (2) were 47 and 38, respectively. Linearity was in the range of 2-8 µg/band for (1) and (2). Limits of detection and quantification were found to be 50 and 150 ng/zone for (1). Precision was below 2 %. The intermediate/inter-day/intra-day precision was 0.4 % (n = 6). Recovery (by standard addition) was in the range between 99.8-101.5 %. Tocopherol acetate was better separated from tocopherol using normal phase TLC than by reversed phase TLC.

J. Planar Chromatogr. 24, 264-267 (2011). TLC of crebanine on silica gel with toluene - ethyl acetate - methanol 14:3:3 in a twin-trough chamber saturated for 1 h at 25 +/- 2 °C. Detection under UV light at 254 nm. Quantitative determination by densitometry in absorbance mode at 286 nm. The method precision (%RSD, n = 3) and the instrument precision (%RSD, n = 6) were 0.9 and 0.5 %, respectively. The repeatability (%RSD, n = 5) was 0.8; the accuracy as average recovery was 100.1 %. The limit of detection and quantification was 10 and 15 ng/zone, respectively. Linearity was between 100-500 ng/zone. The hRf value was 54.

Indian Drugs 48(4), 49-55 (2011). HPTLC of hydrochlorothiazide (HCZ), amlodipine besylate (AMB) and valsartan (VAL) on silica gel with ethyl acetate - methanol - 10 % ammonia 17:4:2. The hRf value was 26 for AMB, 34 for VAL and 82 for HCZ. The linearity range was 100-700 ng/band for VAL and HCZ and 50-400 ng/band for AMB.

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 %.

Planta Med. 77, 548 (2011). HPTLC of forskolin and extracts from rhizomes of Coleus forskohlii on silica gel with toluene - methanol 12:1. The hRf value of forskolin was 27. Anisaldehyde-sulfuric acid reagent was used for spraying followed by heating of the plate at 105 °C for 5 min. Quantitative determination by densitometric scanning in absorbance mode at 545 nm.