用茚三酮显色反应测定烟草中氨基酸含量

Determination on Amino Acids Contents in Tobacco by Ninhydrin Color Reaction

应用茚三酮与氨基酸的显色反应,采用分光光度法测定烟草中氨基酸的含量。分析并确定了试验条件:磷酸盐缓冲溶液的pH值6.70,用量为1.0ml;最大吸收波长为570nm;2%茚三酮溶液的用量为1.5ml。试验考察了显色反应时间及稳定性。用未显色的样液作参比,消除了样液基体中的色素和杂质对检测结果的影响,提高了测定结果的准确度。此方法操作简便、快捷,灵敏度高,检测成本低,特别适用于烟草研究中数量少、批次多的检测。

Amino acids content in tobacco was determined by spectrophotometric method using ninhydrin color reaction. The experimental conditions was analyzed and determined as follows ： 1.0 ml of phosphate buffer （ pH 6.70） ; maximum absorption wavelength, 570 nm; and 1.5 ml of 2% ninhydrin solution. The coloring time and stability were also studied. The sample solution having no color reaction was used as reference, which eliminated the effects of pigments and impurities in the liquid on detection and improved accuracy. This method is simple, fast, highly sensitive, low-cost, and especially suitable for detection of small quantity and multiple batches in tobacco research.