J. Liq. Chrom. & Rel. Technol. 19, 969-975 (1996). TLC of 22 amino acids on silicic impregnated glass fiber sheets with isopropanol - water 7:3, developed for 8 hours. Detection by spraying with 0.25 % solution of ninhydrin in 95 % ethanol and heating at 105°C for 5 min. Also separation of radioactive labeled amino acids.

J. Liq. Chrom. & Rel. Technol. 24, 2525-2530 (2001). HPTLC of creatine on silica gel (after precleaning with dichloromethane - methanol 1:1) with acetonitrile - deionized water 7:3; development in a vapor-equilibrated chamber. The plate was dried for 10 min with a hair dryer, and heated for 5 min at 160°C. Densitometry at 254 nm. Accuracy was found to be within 0.2% of the certified value, and precision was 3-4% relative standard deviation.

Acta Chrom. 13, 161-171 (2003). Lysine and threonine were separated and quantitatively determined from the mixture of amino acids present in a commercially available drug. TLC of alpha-amino acids on layers prepared from a 1:4 stannic arsenate – cellulose mixture with a variety of mobile phases. Best separation was achieved with n-butanol – formic acid – water 7:2:1; or isopropanol – acetic acid – water 8:1:1, or isopropanol – formic acid – water 7:2:1. Detection by dipping in 1 % ninhydrin in butanol after heating at 60 °C . Quantitative determination by spectrophotometry with hydrindantin–methyl cellosolve reagent.

J. Planar Chromatogr. 20, 165-171 (2007). TLC of 17 DL amino acids derivatized with1-fluoro-2,4-dinitrophenyl-5-L-alaninamide, 1-fluoro-2,4-dinitrophenyl-5-L-phenylalaninamide, or 1-fluoro-2,4-dinitrophenyl-5-L-valinamide on silica gel with phenol - water 3:1 or on RP-18 with mobile phases containing acetonitrile and triethylamine-phosphate buffer (50 mM, pH 5.5) with saturation for 10-15 min.

Indian Drugs 47(2), 71-74 (2010). HPTLC of irbesartan and hydrochlorothiazide on silica gel with acetone - chloroform - ethyl acetate - methanol 6:6:6:1. The plates were preconditioned for 10 min in a saturated chamber prior to development. The hRf value of irbesartan was 27 and of hydrochlorothiazide 37. The linearity was 1500-9000 ng/band and 125-750 ng/band for irbesartan and hydrochlorothiazide respectively. The average recovery for both drugs was 99.4-99.5 %.

J. Liq. Chromatogr. Relat. Technol. 37, 829-840 (2014). HPTLC of amino acids such as leucine (1), isoleucine (2), phenylalanine (3), tyrosine (4), alanine (5), lysine (6), proline (7), serine (8), glutamic acid (9), methionine (10), arginine (11), histidine (12) and tryptophan (13) on silica gel with n-butyl acetate – n-butyl alcohol – ethylene glycol 3:5:2. Detection by spraying with ninhydrin (0.3 % in acetone). The hRF values for amino acids (1) to (13) ranged between 9 and 74. The LODs for (5) and (6) were 100 ng/zone and 60 ng/zone, respectively.

J. Liq. Chromatogr. Relat. Technol. 41, 595-603 (2018). Review on different applications of planar chromatography for the analysis of essential and non-essential amino acids and their derivatives, including the use of ninhydrin and other spray reagents for the detection of amino acids by TLC and the formation of color using 6-pyridin-2-yl-5,6-dihydro-benzo[4,5]imidazo [1,2-c] quinazoline and chloranil.

J. High Resol. Chromatogr. 8, 69-72 (1985). HPTLC of 12 metabolites of the tryptophan-NAD pathway in rat urine on cellulose using 5 multiple developments with 4 solvent systems. a) isopropanol -6N NH3 8:1 b) upper layer of butanol - water -5N acetic acid 60:20:3, c) isopropanol -1.6 N NH3 16:1, d) propanol -14 N NH3 - methanol 5:2:1. Densitometry at 254 nm.