Derivative spectroscopy in conjunction with thin layer chromatography applied for determination of mixtures of amino acids in baby food.

The preparative thin layer chromatography using silica gel and solvent systems n. butanol : acetic acid: water ( 4.1 : 1 V/V) and 96\% ethanol : water ( 70 : 30 v/v) were used to separate the amino acids mixture into groups that can be eluted and one or two of amino acids can be determined by derivative spectroscopy. This was done for determining histidine in presence of cystine, arginine in presence of lysine and ornithine, tryptophan in presence of tyrosine and phenylalanin, and methionine in presence of aspartic acid. The proposed method is applied for determination of these amino acids in baby food, Neslac, Dialac and Nestogen. The statistical analysis of the results were found to be good and in agreement with the ion exchange chromatographic method.