Talanta 37, 1105-1106 (1990). Report of a new visualization technique for the detection of amino acids on silica. Spraying with oxalic acid, dithiooxamide, or dithizone solution followed by spraying with ninhydrin solution. The method may be used to identify some of amino acids directly and assist in their detection.

Japanese J. Med. & Pharm. Res. (Kyakuhin Kenkyu) 23, 49-52 (1992). TLC of 8 amino acids on reverse phase layers, impregnated with a copper salt and an optically active amino acid, solvent used: acetonitrile - water - methanol 4:2:1 for tryptophane, acetonitrile - water - propanol 3:4:2 for leucine and isoleucine, and acetonitrile - water - propanol 3:1:1 for phenylalanine. Detection limits between, 0.1 - 2 mM; 0.2 - 1.3% of D-amino acid in L-amino acid were detected.

J. West China Univ. Med. Sci. (Huaxi Yike Daxue Xuebao) 24, 194-197 (1993). Presentation of a novel stable fluorescent reagent CGE(N) for the detection of compounds containing amino groups with TLC detection of glucine as example. Fluorescent excitation at 277 nm and emission wavelength of the spot at 356 nm, resp. Detection limit of 240 ng/spot.

Anal. Letters 28, 2041-2048 (1996). TLC on silica with acetonitrile - water 2:5 containing 2-o-[(R)-2-hydroxypropyl]-b-CD as additive. Detection by spraying with a solution of 1.5 g salicylaldehyde in 100 mL toluene and heating at 50 °C for 10 min.

Separation of the main protein amino acids in a double-layer system. J. Planar Chromatogr. 11, 5-11 (1998). Demonstration of the theoretical aspects of the long-distance development, the basic elements of the double layer cassette for personal OPLC instrument, and the first results in the field of amino acid analysis with special emphasis on the 20 main protein amino acids. HPTLC on single and on double silica gel plates with butanol - acetonitrile - 0.005 M potassium dihydrogen phosphate - acetic acid 1:5:3:1. Detection after treatment with ninhydrin reagent at 490 nm.

J. Planar Chromatogr. 13, 191-194 (2000). Quantitative TLC determination of L-tryptophan on silica gel with 2-propanol - 25 % NH3 7:3. Visualization of amino acids by dipping into a solution of 300 mg ninhydrin in acetone/acetic acid 97:3. Detection of L-tryptophan by treatment with 4-dimethylaminobenzaldehyde and heating at 110°C for 7-10 min. Quantitation by densitometry at 625 nm. Rapid method for determination of L-tryptophan.

Acta Chromatographica 14, 60-69 (2004). TLC on silica gel with 1-butanol - glacial acetic acid - water 3:1:1 with chamber saturation. Detection by spraying with ninhydrin reagent (0.3 g ninhydrin in 100 mL 1-butanol plus 2 mL glacial acetic acid), followed by heating at 110 ºC for several min. Quantification by densitometry at 495 nm. Validation of the accuracy by analysis of spiked blank and standard addition samples and precision by performing replicate analysis on a single day and on different days. Recoveries and RSD for spiked blank and standard addition samples were 98.8 % and 98.5 %, 1.92 % and 0.67 %, respectively. Discussion of use of the method for the routine quality control of nutritional supplements.

Acta Chimica 120, 23-28 (1985). TLC study of chemically reactive synthetic derivatives of peptide hormones and hormone fragments. TLC on silica with ethyl acetate - pyridine - acetic acid - water 240:20:6:11 (S1), ethyl acetate - pyridine - acetic acid - water 120:20:6:11 (S2), ethyl acetate - pyridine - acetic acid - water 60:20:6:11 (S3), ethyl acetate - methanol 5:1 (S4), butanol - acetic acid - water 4:1:1 (S5), ethyl acetate - pyridine - acetic acid - water 30:20:6:11 (S6). Boc-lys(Z)-tyr-gly-gly-phe-leu-OMe (S1), boc-lys-tyr-gly-gly-phe-leu-OMe (S3), boc-lys(Q)-tyr-gly-gly-phe-leu-OMe (S4 and S2), H-lys(Q)-tyr-gly-gly-phe-leu-OMe.HCl (S2 and S4), H-lys-tyr-gly-gly-phe-leu-OMe.2 CH3COOH (S6), Q-tyr-gly-gly-phe-leu-OH (S2 and S5). Detection visual and under UV 254 nm.