J. Sep. Sci. 43, 2981-2988 (2020). HPTLC of citicoline (1) and piracetam (2) in presence of their degradation products on silica gel with methanol - chloroform - ammonium chloride buffer 9:1:2. Quantitative determination by absorbance measurement at 230 nm. The hRF values for (1) and (2) were 15 and 85, respectively. Linearity was between 0.2 and 4 µg/zone for both (1) and (2). Intermediate precision was below 2 % (n=3). The LOD and LOQ were 56 and 180 ng/zone for (1) and 53 and 170 ng/zone for (2), respectively. Average recovery was 100.9 % for (1) and 99.8 % for (2).

J. Planar Chromatogr. 33, 219-229 (2020). HPTLC of carbamazepine (1) and its degradation product iminostilbene (2) on silica gel with petroleum ether - acetone 7:3. Quantitative determination by absorbance measurement at 230 nm. The hRF values for (1) and (2) were 12 and 63, respectively. Linearity was between 0.1 and 1.4 µg/zone for (1) and 0.1 and 1.2 µg/zone for (2). Intermediate precision was below 2 % (n=3). The LOD and LOQ were 0.03 and 0.09 µg/zone for (1) and 0.03 and 0.09 µg/zone for (2), respectively. Average recovery was  99.7 % for (1) and 99.7 % for (2).

Food Control. 22, 1154-1157 (2011). TLC of histamine in fish and fishery products on cellulose with ammonia - ethanol 1:3. Detection by spraying with Pauly's reagent (equal mixture of 20 mM sulfanilic acid in a 1 M HCl solution and 200 mM sodium nitrite solution, followed by adding 10 % anhydrous sodium carbonate in a 5 % ethanol solution). Color intensity was recorded using a digital camera, followed by imaging processing. Linearity was between 30 and 1000 ng/zone for histamine. Intermediate precision was below 5 % (n=3). The LOD was 20 ppm (2 mg/100 g). Recovery rate was between 93 and 98 %.

Food Control. 103, 111-118 (2019). Thin layer chromatography in tandem with surface-enhanced Raman scattering (TLC-SERS) of histamine in tuna samples on diatomaceous earth plates with ethanol - ammonia 3:1. Detection by spraying with Pauly's reagent (equal mixture of 20 mM sulfanilic acid in a 1 M HCl solution and 200 mM sodium nitrite solution, followed by adding 10 % anhydrous sodium carbonate in a 5 % ethanol solution). Gold nanoparticles were deposited on the plate zone and measurements were performed using a Raman spectrometer with an excitation laser wavelength of 785 nm.

J. Ethnopharmacol. 235, 361-374 (2019). HPTLC of colchicine (1) and withaferin A (2) in the polyherbal ayurvedic formulation Peedantak Vati (PV) on silica gel with chloroform - 
methanol - water - formic acid 140:13:2:4. Quantitative determination by absorbance measurement at 218 nm. The hRF values for (1) and (2) were 22 and 28, respectively. LOD and LOQ were 40 and 120 ng/zone for (1) and 120 and 240 ng/zone for (2), respectively.  

Chromatographia 64 (7-8), 423-427 (2006). TLC of six polyamines (ornithine, citrulline, putrescine, cadaverine, spermidine and spermine) on calcium sulfate (CaSO4) and silica gel with 11 different mobile phases, using methanol as the solvent to enhance selectivity and produce differential Rf values. On CaSO4 better separation was achieved than on silica gel, no derivatization is needed, and development time is about 1/3 shorter. Quantitative determination by absorbance measurement at 550 nm after extracting substances from the plates and eluting from the coating material. Limit of detection (LOD) was 750 ng, limit of quantification (LOQ) was 1880 ng. Quantitative separation of underivatized polyamines in spiked human urine samples.

Biomed Chromatogr. 7, 315-316 (1993). TLC of norepinephrine, serotonine and dopamine in rat brain on silica with dichloromethane - acetone - ethyl acetate - methanol 140:60:4:1. Detection by spraying with ethylene diamine - methanol - 0.5% potassium ferricyanide 10:40:10, and incubating for 7 min. at 60°C. Quantification by fluorodensitometry 415/>495 nm.

Asian Journal of Chemistry 22(8), 5951-5955 (2010). TLC on silica gel with cyclohexane - methanol - ethyl acetate - 25 % ammonia 10:3:6:1. The hRf value was 7 for atenolol and 69 for nifedipine. Densitometric evaluation at 230 nm. The linearity was in the range of 3-21 µg/band for atenolol and 1.2-8.4 µg/band for nefidipine. The recovery was 100.7 % for both drugs. The method was found suitable for analysis of the combined dosage form of atenolol and nefidipine without interference of excipients.