J. Chromatogr. Sci. 53 (9) 1603-1610 (2015). TLC of two antidiabetic drugs, glimepiride and metformin HCl in pure and tablet form as a binary mixture, or subjected to acidic, basic, oxidative and photo-degradative stress, by using an optimized salting out stability-indicating and kinetic TLC technique (SOTLC) on silica gel with aqueous ammonium sulfate – acetonitrile 7:3. The hRf value of glimepiride was 26±2 and of metformin HCl 73±2. Quantitative determination by densitometry at 237 nm in the concentration range of 60-1400 ng/zone for both drugs. The correlation coefficient of the calibration curve was 0.996 for glimepiride and 0.997 for metformin HCl.

J. Ethnopharmacol. 198, 158-166 (2017). HPTLC of chlorogenic acid in the stems of Solanum xanthocarpum on silica gel with ethyl acetate – glacial acetic acid – formic acid – water 8:3:3:4. Quantitative determination by absorbance measurement at 254 nm. The hRF value for chlorogenic acid was 56.

J. Ethnopharmacol. 202, 97-102 (2017). HPTLC of betaine in the roots of Achyranthes aspera on silica gel with methanol – water 9:1. Detection by spraying with Dragendorff's reagent, followed by 10 % ethanolic sulfuric acid and drying at 110 °C for 5 min. Quantitative determination by densitometry at 520 nm. The hRF value for betaine was 36. Linearity was between 1 and 5 μg/band. The intermediate precision was below 2 % (n=6). LOD and LOQ were 0.13 μg/mL and 0.10 μg/mL, respectively. (Note: The reported LOD and LOQ do not make sense, as LOD is higher than LOQ.)

Chinese J. Hosp. Pharm. 35 (4), 288-292 (2015). Zhichuang Xunxi Ye fumigant is a herbal TCM for the treatment of hemorrhoids. For quality control, TLC of its extracts, (1) for Leatherleaf Mahonia Stem, on silica gel preconditioned with ammonia vapor and developed with toluene – ethyl acetate – methanol – isopropanol - ammonium hydroxide 12:6:3:3:1, detection at UV 366 nm; (2) for Radix sophorae flavescentis, on silica gel impregnated with 2 % NaOH, with (A) toluene – acetone – methanol 16:6:1, (B) the upper phase of toluene – ethyl acetate – methanol – water 2:4:2:1 under 10 ºC overnight, detection by spraying with 5 % potassium iodobismuthate in HCl – water 1:200 and evaluation in daylight; (3) for Phellodendron Chinense Schneid., on silica gel with chloroform - methanol – water 30:15:4, detection by spraying with 5 % potassium iodobismuthate in HCl – water 1:200 and evaluation in daylight. Quantification of berberine chloride hydrate and matrine by HPLC.

J. Chromatogr. A 1529, 93-106 (2017). Presentation of the quantitative effect-directed profiles of 77 industrially and freshly extracted botanicals like herbs, spices, vegetables and fruits, widely used as food ingredients, dietary supplements or traditional medicine for their quality assessment with regard to potential health-promoting activities. Fast assignment of single active compounds and evaluation of their contribution to the overall activity, originating from a food or botanical sample by combination of HPTLC hyphenated with UV/Vis/FLD detection and effect-directed analysis, using the 2,2-diphenyl-1-picrylhydrazyl radical, Gram-negative Aliivibrio fischeri, Gram-positive Bacillus subtilis, acetylcholinesterase and tyrosinase assays. Characterization of bioactive compounds of interest eluted using an elution head-based interface by HPTLC-UV/Vis/FLD-EDA-ESI-(HR)MS method. Demonstration of the excellent quantification power of the method by applying for rosmarinic acid, contents ranged from 4.5 mg/g (rooibos) to 32.6 mg/g (rosemary), for kaempferol-3-glucoside from 0.6 mg/g (caraway) to 4.4 mg/g (wine leaves), and for quercetin-3-glucoside from 1.1 mg/g (hawthorn leaves) to 17.7 mg/g (thyme). The mean repeatabilities (%RSD, n=18) were ≤ 2.2 % for the three compounds and the mean intermediate precision (%RSD, n=3) was 5.2 % over three different days.

J. Chromatogr. A 1506, 109-119 (2017). HPTLC of seven important steviol glycosides on silica gel, which may degrade in food products under certain processing and storage conditions, and additionally as a sum parameter their reported breakdown products steviol and isosteviol. Detection with 2-naphthol and primuline reagent. Baseline separation of steviol and isosteviol was achieved after a plate cut and subsequent short development (two-step method). The HPTLC method was robust with regard to varying sample matrix loads, provided a high sample throughput (23 separations in parallel on one plate), and was fast (total analysis time of 1 h: 30 min application, 15 min separation and 15 min derivatization/densitometry, leading to 2.6 min per sample). The solvent consumption was low (0.4 mL per analysis) and accuracy of the densitometric quantification was good. Confirmation of the results with HPTLC-ESI-MS of only the zones of interest instead of matrix or background so that there was less need for MS cleaning. Hyphenation to Aliivibrio fischeri bioassay to obtain information on bioactive compounds in Stevia leaf extracts.

Rev. Bras. Farmacogn. 28/1, 92-101 (2018). HPTLC fingerprint of Eugenia uniflora on silica gel with ethyl acetate – formic acid – water 18:1:1. Detection by spraying with natural products reagent followed by PEG reagent. Qualitative identification under UV 365 nm. The hRf values of gallic acid, myricetrin and ellagic acid were 71, 34 and 38, respectively.

J. Chromatogr. A 1526, 157-166 (2017). Introduction of a promising alternative method for protein analysis using HPTLC with its high level of variability regarding the chromatographic system (multiple mobile and stationary phases, even mixed) and manifold detection as well as hyphenation possibilities. Silica gel, cellulose, and different RP layers were investigated with regard to their applicability for HPTLC-immunostaining. HPTLC of intact proteins on silica gel with 2-butanol – pyridine – ammonia – water 39:20:10:31; on cellulose with 2-butanol – pyridine – ammonia – water 32:30:11:25; and on RP phase with acetonitrile – trifluoroacetic acid – water 400:30:37. After development the plate was incubated with Tween20 as blocking reagent in a small vessel to inhibit unspecific binding of the antibodies to the surface. Then the plate was incubated for 2 h with the primary antibody solution and after washing with the secondary antibody for 1 h. Detection by incubating the plate in a dying solution containing 0.06% 3,3',5,5'-tetramethylbenzidine, 0.2% dioctyl sulfosuccinate sodium salt, 0.7% citric acid monohydrate, 1.8% sodium hydrogen phosphate dihydrate, 25% ethanol, and 1.5‰ dihydrogen dioxide, until blue zones appeared under white light. For the example analysis of beta-lactoglobulin on silica gel using antibovine beta-lactoglobulin antibodies, linearity was in the range of 75-2000 ng, the LOD was 62 ng/zone, the LOQ 93 ng/zone, and the accuracy 98.3%.