IPA Convention, 2010, RA-PO 35. HPTLC of citicoline sodium in tablet formulation on silica gel with chloroform - methanol - water 3:7:3. The compound was well resolved with an hRf value of 53. Densitometric measurement at 280 nm. The method was linear in the range of 300-900 ng/band. HPLC analysis was performed on RP18 column using 1 % formic acid - methanol 19:1. Results obtained with either method were comparable.

Anal. Biochem. 409 (2), 249-259 (2011). Presentation of a less time-consuming, more sensitive, and more precise method for the quantitative determination of nucleoside triphosphates (NTPs), 5-ribosyl-1-pyrophosphate (PRPP), and inorganic pyrophosphate (PPi) in cell extracts by TLC: Separation of an acid extract of L. lactis by charcoal filtration into a filtrate and an eluate, which then was separated by TLC either in the Cashel solvent (0.85 M potassium phosphate, pH 3.4) or in the AFC solvent (3 M ammonium formate [pH 2.4] and 0.7 M ammonium chloride). Two-dimensional separation of 18 µL of the eluate sample using the AFC solvent in the first dimension and using 0.75 M LiCl in 7.5 % lithium borate (pH 6.8, borate solvent) in the second dimension.

Acta Chromatographica 22 (2), 227-236 (2010), DOI:10.1556/AChrom.22.2010.2.6. TLC of piperine, the bioactive constituent of black pepper (Piper nigrum), on silica gel with dichloromethane – ethyl acetate 9:1 at 30 °C in a twin-trough chamber saturated for 30 min. Detection under UV light at 254 nm and documentation with a digital camera. Based on the image a density profile plot was established by Scion Image software, which allowed to calculate the concentration of piperine by comparison of the peak areas of samples and piperine standards. The linearity was in the range of 24-84 ng/zone (r2=0.9927). The limits of detection and quantitation were 0.35 and 1.05 ng/zone, respectively. Precision (repeatability, n=6) and intermediate precision (2 days, n=12) both are below 2.6 %RSD. Recovery is between 96.7-101.4 %.

J. Chromatogr. A 1218 (19), 2745-2753 (2011). HPTLC of sucralose in waste water on silica gel with isopropyl acetate – methanol – water 15:3:1. The developing time was 15 min. Detection with p-aminobenzoic acid reagent. Quantification by absorbance measurement at 400 nm. The limit of quantification was 100 ng/L at a recovery rate of 80 % and the extraction of a 0.5 L water sample. An interlaboratory trial in 2008 showed good agreement of the sucralose content determined in four water samples by HPTLC and other methods (HPLC–MS/MS or HPLC–TOF-MS). The good accuracy and high sample throughput capacity proved HPTLC as a well suited method for quantification of sucralose in various aqueous matrices.

Journal of Pharmacy Research 4(3), 643-644 (2011) TLC of doxofylline on silica gel with acetonitrile - methanol 7:3. The hRf of doxofylline was 66. Quantitative determination at 208 nm. The method was found to be linear in the range of 100-600 ng/band with an average recovery of 99.7 %. The results by TLC were comparable with results obtained by RP-HPLC.

J. of China Pharm. 26 (2), 150-154 (2012). Some health foods were illegally mixed with certain kinds of medicine which may harm the health of consumers. For example antidiabetics like glibenclamide, glipizide and gliclazide were illegaly added to health foods marketed for adjusting blood sugar. Presentation of TLC and UV methods for detection of these illegal additives. TLC on silica gel with chloroform – petroleum ether (60-90 ºC) – methanol – glacial acetic acid 8:14:1:1, detection at UV 254 nm. The methods were applied to three varieties of real life samples and the results showed no difference to those obtained by LC-MS.

J. Liq. Chromatogr. Relat. Technol. 36, 2387-2394 (2014). The image processing programs ImageJ and Sorbfil TLC Videodensitometer were compared to study direct antioxidant properties of compounds separated from extracts obtained from Medicago sativa. Comparable results were obtained based on built-in functions present in both programs for processing TLC videoscans.

J. Planar Chromatogr. 27, 287-293 (2014). HPTLC of ciprofloxacin HCl (1) and moxifloxacin HCl (2) in industrial wastewater on silica gel with methanol - ammonia - methylene chloride 11:7:4. Quantitative determination by absorbance measurement at 278 nm. The hRF values for (1) and (2) were 43 and 54, respectively. Linearity was in the range of 250-2500 ng/zone for (1) and 1000-50000 ng/zone for (2). The intermediate/interday/intra-day precisions were below 1 % (n=3). The LOD and LOQ were 110 ad 335 ng/zone for (1) and 101 and 305 ng/zone for (2), respectively. Recoveries were between 79.6 and 91.5 % for both (1) and (2). Results were comparable to a HPLC method.