J. Liq. Chromatogr. Relat. Technol. 38, 1088-1093 (2015). HPTLC of tramadol hydrochloride in pharmaceutical formulation on silica gel with ethyl acetate - methanol - ammonia 90:8:5. Quantitative determination by absorbance measurement at 271 nm. The hRF value of tramadol hydrochloride was 64. Linearity was in the range of 1000-6000 ng/zone. Intra-day and inter-day precisions were below 2 % (n=3). Mean recoveries were found to be around 100 %.

Phytochemistry. 117, 554-568 (2015). Review of the bioactive markers for quality control of products containing gingerols and shogaols from the rhizomes of ginger (Zingiber officinale). HPTLC of gingerol in ginger rhizomes and Ayurvedic products on silica gel with n-hexane - diethyl ether 2:3 (1) or n-hexane - acetone 18:7 (2). The hRF value of gingerol was 40 with (1) and 23 with (2).

J. Planar Chromatogr. 28, 426-435 (2015). HPTLC of methyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate, propyl 4-hydroxybenzoate and butyl 4-hydroxybenzoate on silica gel with petroleum ether - acetic acid 20:3. Quantitative determination by absorbance measurement at 254 nm. The influence of experimental settings on densitometric evaluation using the TLC Scanner 4 was investigated to assess the impact on signal intensities, peak shape/resolution and quantitative results. Peak positions can shift for up to 0.5 mm for fast scan speeds. For improved quantitative results the scan slit length should be set to 75 % of the band length, the scan speed to 5 or 10 mm/s and data resolution to 25 or 50 μm/step. The resolution mode of the optical system provided higher signal intensities compared to the light mode. Peak broadening was observed for higher scan speeds, whereby the signal height decreased significantly, if compared to the peak area evaluations. The effects of the instrumental settings on the signal intensity were less pronounced for the evaluations via peak area. Hence, peak area evaluations were more robust with regard to the changed settings.

J. Planar Chromatogr. 28, 395-397 (2015). HPTLC of 25-B-NBOMe (a N-(2-methoxy)benzyl-substituted phenylethylamine hallucinogen) in seized blotters (small, square pieces of absorbant paper impregnated with LSD or other hallucinogens) on silica gel with cyclohexane – toluene – diethylamine 15:3:2. Quantitative determination by absorbance measurement at 298 nm. The hRF value for 25-B-NBOMe was 34. Linearity was in the range of 19-115 μg/zone. LOD and LOQ were 7 and 22 μg/zone. The intermediate precision was below 6.3 % (n=6). Average recovery was 98 %.

J. Ethnopharmacol. 190, 116-141 (2016). This review discusses the progress in chemical analysis of Angelica sinensis and its preparations. The study describes TLC as a rapid separation method and qualitative analysis technology that is commonly used for routine chemical analysis of A. sinensis. The advantages of the technique as well as TLC systems using ferulic acid and ligustilide as markers were described.

seed (Takhmaria). J. Planar Chromatogr. 29, 216-220 (2016). HPTLC of apigenin in the seeds of Ocimum basilicum on silica gel with toluene – acetone – formic acid 5:4:1. Quantitative determination by absorbance measurement at 340 nm. The hRF value of apigenin was 71. Linearity was in the range of 100-600 ng/zone. Intermediate precisions were below 0.5 %. The LOD and LOQ were 4 and 12 ng/zone. Recovery was between 98.5 and 100.6 %.

J. Planar Chromatogr. 29, 203-208 (2016). HPTLC of bacoside A in Bacopa monnieri on silica gel with ethyl acetate – methanol – water – butanol 160:25:16:5. Detection by spraying with anisaldehyde – sulfuric acid reagent followed by heating at 105 °C for 5 min. Quantitative determination by absorption measurement at 525 nm. Linearity was in the range of 160-480 ng/zone. Intermediate precisions were below 1.3 %. The LOD and LOQ were 40 and 120 ng/zone. The method was performed to check the chemical diversity in Bacopa in relation to bacoside A.

J. Planar Chromatogr. 29, 195-202 (2016). HPTLC of naftopidil on silica gel with toluene – ethyl acetate – methanol – triethylamine 80:20:5:3. Quantitative determination by absorbance measurement at 254 nm. The hRF value was 52. Linearity was in the range of 500-2500 ng/zone. Intermediate precisions were below 1.5 %. The LOD and LOQ were 95 and 268 ng/zone. Average recovery was 100.0%.