J. Planar Chromatogr. 27, 58-65 (2014). HPTLC of ternary mixtures of cetirizine dihydrochloride (1), pseudoephedrine (2), and/or phenylpropanolamine (3) and paracetamol (4) on silica gel with methanol - water 199:1. Quantitative determination by absorbance measurement at 257 nm. The hRF values for compounds (1) to (4) were 66, 16, 23 and 83, respectively. Linearity was in the range of 1-4 µg/zone for (1), 3-10 µg/zone for (2), 4-8 µg/zone for (3) and 5-100 µg/zone for (4), respectively. The intermediate/interday/intra-day precisions were below 2 % (n=5). The LOD and LOQ were 0.3 and 1 µg/zone for (1), 0.9 and 3 µg/zone for (2), 1.2 and 4 µg/zone for (3) and 1.5 and 5 µg/zone for (4), respectively. Mean recoveries for (1) to (4) were close to 100 %.

J. Sep. Sci. 37, 2797-2804 (2014). HPTLC of six flavonoids ((1) rutin, (2) luteolin-7-o-glucoside, (3) chamaemeloside, (4) apigenin-7-o-glucoside, (5) luteolin, (6) apigenin) and one coumarin, (7) umbelliferone, from chamomile plant samples and dietary supplements on amino silica gel with dichloromethane - acetonitrile - ethylformate - glacial acetic acid formic acid 44:10:12:5:5. Detection by spraying with 1 % methanolic solution of diphenylboric acid-beta-ethylamino ester, followed by air drying at 50 °C for 5 min. Quantitation by absorbance measurement at 450 nm for (1), (2) and (5), 360 nm for (3), (4) and (6) and 320 nm for (7). The hRF values for (1) to (7) were 7, 22, 27, 33, 58, 69 and 77. Linearities were in the range of 30-240 ng/zone for (1), 40-160 ng/zone for (2), 55-220 ng/zone for (3), 50-200 ng/zone for (4), 16-65 ng/zone for (5), 30-120 ng/zone for (6) and 21-85 ng/zone for (7). The intermediate intra-day and inter-day precisions were below 5 %. The LOD and LOQ were 10 and 30 ng/zone for (1), 13 and 40 ng/zone for (2), 18 and 55 ng/zone for (3), 17 and 50 ng/zone for (4), 6 and 16 ng/zone for (5), 10 and 30 ng/zone for (6) and 7 and 21 ng/zone for (7), respectively. Recoveries for the compounds were >90 %.

J. Planar Chromatogr. 27, 392-397 (2014). HPTLC of (1) rifampicin, (2) isoniazid, and (3) pyrazinamide in a dosage tablet on silica gel with ethyl acetate – acetone – methanol – glacial acetic acid 18:5:5:2. Quantitative determination by absorbance measurement between 200 and 800 nm. The hRF values of (1) to (3) were 25, 44 and 74, respectively. Linearities were in the range of 250-600 ng/zone for (1), 125-300 ng/zone for (2) and 625-1500 ng/zone for (3). The intermediate precision was below 2.3 % (n=6) . Mean recoveries for (1) to (3) were 100.0, 98.6 and 99.4 %, respectively.

salina, and NMR profiles of extracts of lichens collected from Brazil and Antarctica. Quim. Nova. 37, 1015-1021 (2014). TLC of (1) atranorin, (2) salazinic, (3) barbatic, (4) alpha-alectoronic, (5) alpha-collatolic, (6) cryptochlorophaeic, (7) caperatic, (8) lobaric and (9) protolichesterinic acids in six lichen species named Parmotrema cetratum (Ach.) Hale (I), Parmotrema wainioi (A. L.Smith) Hale (II), Canoparmelia cryptochlorophaea (Hale) (III), Parmotrema mesotropum (Müll. Arg.) Hale (IV), Cladia aggregata (Sw.) Nyl. (V) and Stereocaulon alpinum Laurer (VI), on silica gel with toluene - ethyl acetate - acetic acid 6:4:1 for (I, IV and V) and toluene - acetic acid 17:3 for (II, III and VI). Detection by spraying with p-anisaldehyde - sulfuric acid, followed by heating at 110 ºC. The hRF values of (1) and (2) in (I) were 73 and 33, respectively, whereas the value of (3) and (4) in (II) were 15 and 36; the value of (1) in (III) was 71. DPPH radical scavenging activity was also investigated.

leaves by a validated HPTLC–photodensitometry method. Phytochem. Anal. 26, 253-260 (2015). HPTLC of oleacein (1), oleuropein (2) and echinacoside (3) in the leaves of Ligustrum vulgare on silica gel with dichloromethane - methanol - formic acid - water 160:50:8:3. Detection by dipping into anisaldehyde (0.5 %, methanolic) and sulfuric acid (5 %, methanolic), followed by heating at 105 °C for 10 min. Quantitative determination by absorbance measurement at 240 nm and 350 nm. The hRF values of (1) to (3) were 82, 58 and 12, respectively. Linearity was in the range of 625-1875 μg/mL for (1), 100-300 μg/mL for (2) and 180-540 μg/mL for (3). LOD and LOQ were 0.58 and 1.77 μg/mL for (1), 0.20 and 0.61 μg/mL for (2) and 0.32 and 0.97 μg/mL for (3), respectively. Intra-day and inter-day precisions were below 3 % (n=3). Average recoveries varied from 102 to 113 % for (1), 106 and 112 % for (2) and 99 and 101 % for (3), respectively.

and species comparison study using high-performance thin-layer chromatography - mass spectrometry. J. Planar Chromatogr. 28, 280-286 (2015). HPTLC of trichostachine (1), piperine (2), 4,5-DHPL (3), guineensine (4), pellitorine (5) and sesamin (6) in Piper longum, Piper chaba and Piper nigrum on silica gel with ethyl acetate - n-hexane - dimethyl amine 40:60:1. Quantitative determination by absorbance measurement at 273 nm for (4) and (5), 294 nm for (3) and (6) and 340 nm for (1) and (2). The method was coupled with MS to identify the 6 markers. The hRF values for (1) to (6) were 12, 36, 46, 71, 78 and 82, respectively. Linearity was in the range of 25-1000 ng/zone for (1) to (6). LOD was between 4 and 7 ng/zone whereas LOQ was between 14 and 20 ng/zone for (1) to (6). The intermediate precision was below 1 % (n=4). Recoveries were in the range of 99-103 %.

J. Planar Chromatogr. 28, 466-471 (2015). TLC of L-glutamic acid in a solution of Astragalus complanatus coarse powder on silica gel with n-butyl alcohol - glacial acetic acid - water 4:1:1. Detection by spraying with 0.2 % ninhydrin - acetone solution 10:1, followed by heating at 105 °C. Quantitative determination by measuring pixels after photographing. Linearity was in the range of 10-60 μg/zone. Average recovery was 103 %. Different measures to reduce the error were proposed.

Rapid Commun. Mass Spectrom. 29, 1288-1296 (2015). HPTLC of sphingomyelins (1), phosphatidylcholines (2) and phosphatidylethanolamines (3) on silica gel with chloroform - methanol - water - acetic acid 30:15:2:4 for the first step and acetone - acetonitrile - chloroform 5:4:2 for the second step. Detection by spraying with 0.5 % amido black 10B stain in 1 M NaCl. The method was coupled with matrix-assisted laser desorption/ionisation mass spectrometry for the analysis of (1) and (2) extracted from 5,6-dimethylxanthenone-4-acetic acid-treated xenograft tumours.