Abstract
The reproducibility of the automatic analysis of amino acids is examined by the repeated determinations. i) The ordinate axis of the recorder sheet of the automatic amino acid analyzer such as HITACHI Type KLA-2 should be longer than 25 cm. ii) Small variations in the elution time of each amino acid do not affect the result of determination. iii) The shape of the peak gives a greater effect on the result, and a well-defined Gaussian curve is required to obtain high reproducibility. iv) The absorbance ratios of 440 mμ/570 mμ, and 440 mμ/650 mμ for the reaction products of 52 amino acid components with ninhydrin were determined. The reproducibilities of the estimated ratios are given for 20 standard amino acids.
