J. Liq. Chromatogr. Relat. Technol. 43, 445-454 (2020). HPTLC of aniline (1), 2,4-xylidine (2) and 4-aminoazobenzene (3) in chili oils, pickles and related food matrices on silica gel with chloroform - acetic acid 9:1. Quantitative determination by absorbance measurement at 280 nm. The hR_F values for (1) to (3) were 53, 43 and 82, respectively. Linearity was in the range of 2-14 ppm for (1) to (3). The LOD and LOQ were 0.0015 and 0.0045 ppm for (1), 400 and 1200 ppm for (2) and 200 and 600 ppm for (3), respectively. Mean recovery rate was 100.2 % for (1) and 100.9 % for (2). The azo aryl amines were also analyzed using a TLC-MS interface.

J. Planar Chromatogr. 33, 43-50 (2020). HPTLC of trigonelline in coffee samples with ethyl acetate - methanol - water - formic acid 54:23:15:8. Quantitative determination by absorbance measurement at 267 nm. The hR_F value for trigonelline was 24. Linearity was between 100 and 700 ng/zone. Intermediate precisions were below 2 % (n=3). The LOD and LOQ were 33 and 110 ng/zone. Recovery rate was between 97.6 and 99.4 %.

Food Addit. Contam. Part A. 36, 1218-1227 (2019). Preparative TLC of florfenicol and florfenicol amine in porcine urine on silica gel with dichloromethane - acetone - ammonium hydroxide 20:20:1. Qualitative identification under UV light at 254 nm. Zones were scraped off and extracted for HPLC analysis.

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. Planar Chromatogr. 32, 411-420 (2019). HPTLC of oleuropein in olive leave samples belonging to 9 different Egyptian olive varieties on RP-18 with methanol - acetonitrile 7:3. Detection by dipping into a methanolic 2-aminoethyldiphenylborane reagent (0.5 %), followed by drying and dipping into methanolic PEG 400 solution (5 %). Qualitative determination under UV light at 366 nm. Captured images were processed using the ImageJ software in order to build 2 separate data matrices (before and after derivatization). Quantitative determination by absorbance measurement at 240 nm. The hRF value for oleuropein was 35. Linearity was between 0.1 and 0.6 µg/zone.  Intermediate precision was below 1 % (n=6). The LOD and LOQ were 0.07 and 0.22 µg/zone. Recovery rate was 100.5 %.

J. Food Compos. Anal. 77, 39-43 (2019). TLC of marine oil omega-3 supplements on silica gel with hexane - diethyl ether - glacial acetic acid 50:10:1. Detection by spraying with anisaldehyde solution, following by heating using a heat gun. Analysis of samples allowed the identification of different sources of omega-3 polyunsaturated fatty acids (PUFA) in their natural triacylglycerol (TAG) or concentrated ethyl ester (EE) forms.

J. Food Compos. Anal. 80, 16-32 (2019). Review of methods and techniques for the analysis of adulterants in honey, including TLC and HPTLC. Originally TLC was used to detect honey adulterated with high fructose corn syrup. HPTLC has been used for the detection of sucrose, fructose or glucose in commercial honeys.