Research of determination of lysine by ninhydrin colorimetry

According to the colorimetry principle of α-amino acid and ninhydrin,the method of quantitative determination of lysine by ninhydrin colorimetry was researched,and the pH value of the solution,dosage of the ninhydrin,heated time and cooled time were investigated in order to find the optimum conditions of determination of lysine by ninhydrin colorimetry.The optimun conditions were as follows:the pH value was 6.0,and the ninhydrin was added 1.0mL,heated 15min and cooled 10min,finally determined at 570nm.