Braz. J. Pharm. Sci. 49, 845-851 (2013). HPTLC of metoprolol (1) and hydrochlorothiazide (2) in human plasma on silica gel with chloroform - methanol - ammonia 18:2:1. Quantitative determination by absorbance measurement at 239 nm. The hRF values for (1) and (2) were 48 and 13. Linearity was in the range of 20-120 μg/zone for (1) and 2-12 μg/zone for (2). The intermediate/interday/intra-day precisions were below 5 % (n=3). The LOQs were 20 and 2 μg/zone for (1) and (2), respectively. Recoveries were between 70.6 and 84.9 %.

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. Planar Chromatogr. 27, 328-332 (2014). HPTLC of crude extracts of micro-algae Dunaliella bioculata, Phaeodactylum tricornutum, and Scenedesmus obliquus on silica gel with dichloromethane - methanol 95:5. Data analysis of pictures digitally acquired at UV 254 nm and UV 366 nm included baseline correction, chromatogram alignment, principal component analysis (PCA) de-noising and diffusion drift correction. The workflow allowed to obtain a peak list containing hRF values, intensities and areas for statistical analysis.

J. Planar Chromatogr. 28, 42-47 (2015). HPTLC of (1) homoeriodictyol and (2) persicogenin in the methanol extract of the aerial parts of Rhus retinorrhoea and Rhus tripartita on silica gel with toluene - ethyl acetate - methanol 16:4:1. Quantitative determination by absorbance measurement at 293 nm. The hRF values of (1) and (2) were 30 and 48. Linearity was between 100 and 800 ng/zone for both, (1) and (2). The intermediate intra-day and inter-day precisions were below 2 % (n=6). The LOD and LOQ were 26 and 77 ng/zone for (1) and 31 and 92 ng/zone for (2), respectively. Recoveries were in the range of 98.9-99.5 % for (1) and 98.3-99.2 % for (2).

J. Planar Chromatogr. 28, 67-73 (2015). HPTLC of (1) rifampicin, (2) isoniazid and (3) piperine on silica gel with toluene – methanol – chloroform 7:3:3. Quantitative determination by absorbance measurement at 300 nm. The hRF values of (1) to (3) were 51, 24 and 81, respectively. Linearities were between 100 and 700 ng/zone for (1) and (2) and between 20 and 90 ng/zone for (3). The intermediate intra-day and inter-day precisions for (1) to (3) were below 2 % (n=6). The LOD and LOQ were 12 and 33 ng/zone for (1), 20 and 53 ng/zone for (2) and 5 and 10 ng/zone for (3). Recoveries for (1) to (3) were in the range of 99-101 %.

J. Planar Chromatogr. 27, 428-430 (2014). HPTLC of (1) tretinoin and (2) isotretinoin on silica gel with toluene – ethyl acetate – methanol 16:2:1. Quantitative determination by absorbance measurement at 334 nm. The hRF values of (1) and (2) were 27 and 38, respectively. Linearity was in the range of 30-70 ng/zone for (1) and (2). The intermediate precision was below 1 % (n=6) for (1) to (2). The LOD and LOQ were 10 and 20 ng/zone for (1) and 20 and 30 ng/zone for (2). Recovery for (1) and (2) were in the range of 95-102 %.

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.

Microbiol. Res. 169, 794-802 (2014). Preparative TLC of a biosurfactant-like compound secreted by Pseudomonas synxantha on silica gel with dichloromethane - methanol 9:1. Detection by iodine vapor. The band with the highest hRF value showed antibacterial activity against M. smegmatis (previously confirmed by spot assay) .