J. Chinese Herb Med. (Zhongcaoyao) 27, 422-426 (1996). TLC of amino acids on silica with chloroform - methanol - formic acid 35:15:1. Detection by spraying with 0.2% ninhydrin in ethanol. TLC of steroids on silica with benzene - petrol ether 4:1. Detection by spraying with acetic anhydride - sulfuric acid - ethanol 1:1:10 and heating at 100°C for 15 min.

Biol. Chem. 379, 59-63 (1998). TLC of tyrosine and 3,4-dihydroxyphenyl-alanine (DOPA), as well as of adrenaline, noradrenaline and dopamine on silica gel with n-butanol ñ acetic acid ñ water 4:1:1. Detection with ninhydrin spray. Rf values: DOPA 0.29, adrenaline 0.36, noradrenaline 0.38, tyrosine 0.41, dopamine 0.43. Measurement of [3H]-radioactivity of DOPA by scintillation counting.

Planta med. 66, 418-423 (2000). TLC of b-pyrazol-1-yl alanine on silica gel with chloroform - methanol - water 13:10:3. Visualization by spraying with 2% methanolic ninhydrin solution and heating at 110°C for 10 min.

J. Planar Chromatogr. 19, 161-166 (2006). HPTLC of 16 amino acids on cellulose in a horizontal chamber with aqueous mixtures of 2-propanol, acetonitrile, and tetrahydrofuran in the range of 60-90 % (10 % increments). Acetic acid (at a concentration of 1%) was only added to the mobile phases containing 2-propanol. Best separation was achieved with tetrahydrofurane - water 17:3; acetonitrile - water 4:1; and 2-propanol - water - acetic acid 89.5 - 9.5 - 1 respectively. The adsorbed solvent was removed before repeating the development process. Visualization by spraying with ninhydrin solution and heating at 105 °C for 1.5-2 min. Densitometric evaluation by absorbance measurement at 415 nm.

Biochem. Biophys. Res. Commun. 394, 448-452 (2010). HPTLC of [14C]-L-arginine and [14C]-L-citrulline of a nitric oxide synthase conversion assay in mitochondria rat liver, on silica gel with butanol - acetic acid - water 3:1:1. Detection by dipping in a solution of 2 % ninhydrin in acetone, followed by heating on a plate heater for 1 min. After visualization, the plates were exposed to X-ray film for 4.5 days.

J. Planar Chromatogr. 26, 517-520 (2013). TLC of amino acids on silica gel with 1-propanol - water 7:3. Detection by spraying with (1) 1 % 2-hydroxybenzenecarbaldehyde solution in propanone; or (2) 1 % 4-bromobenzenecarbaldehyde solution in propanone (2), followed by heating at 110 ºC for 10 min. After cooling, all plates (treated with (1) or (2)) were sprayed with ninhydrin (indane-1,2,3-trione monohydrate) reagent and air dried. Amino acid zones in various shades from yellow to brownish-red were detected (detailed table provided in paper). Plates were heated again at 110°C for 10 min and color changes were recorded. The LOD were determined visually by comparison of standard solutions (1 mg/L) and further dilution until no zone was seen. LOD for (1) and (2) were in the range of 0.1-1.0 µg/zone and 0.01-1.0 µg/zone, respectively.

J. Liq. Chromatogr. Relat. Technol. 41, 373-376 (2018). HPTLC of 22 amino acids in the cultures of control and starved Biomphalaria glabrata snails on cellulose plates with 2-butanol – pyridine – acetic acid – water 39:34:10:26. Detection by spraying with 2 % ninhydrin solution in n-butanol – acetone 1:1, followed by heating at 110 ºC for 10 min. Quantitative determination by absorbance measurement at 610 nm. Samples were also analyzed on RP-18 with water – methanol 3:7 with addition of 100 mM formic acid in the bonded phase normal phase mode and water – methanol 7:3 with the addition of 100 mM trifluoroacetic acid in the bonded phase reversed phase mode. Although better separation results were obtained with the cellulose plates, an excellent separation of the pair Ile and Leu with the RP-18 W was noted.

Chromatography the State of the Art, Vol. II. Akademiai Kiado, Budapest 1985, 591-599. OPTLC on silica and HPTLC chromatoplates with different solvent systems. Modified ninhydrin staining reaction.