不同pH值条件下的丝氨酸标准曲线

Serine standard curves at different pH

根据丝氨酸与茚三酮反应后溶液在570nm处有最大吸光值，用分光光度法测定丝氨酸含量，确定了丝氨酸与茚三酮反应的最佳时间和相对用量．为了准确测定磷脂制备体系中丝氨酸含量，绘制了pH值分别为4．5，5．0，和6．0时的丝氨酸标准曲线．结果表明：pH值为4．5时，丝氨酸的含量与A570值在0～0．20g／L范围内呈良好的线性关系y=5．595x＋0．056（R^2=0．9912）；pH值为5．0时丝氨酸的含量与A570值在0～0．10g／L范围内呈良好的线性关系y=10．59x＋0．023（R^2=0．9985）；pH值为6．0时，丝氨酸的含量与A570值在0～0．04g／L范围内呈良好的线性关系y=37．388x＋0．0052（R^2=0．9915）．

According to the principle of color reaction between α-amino-acids and ninhydrin, ninhydrin spectrophotometric method of determining the serine level has been set up and A570 value was determined. The optimal experimental conditions of ninhydrin-spectrophotometry such as pH, the relative amount of ninhydrin added and reaction time have been investigated. The results showed that： the relationship of the amount of serine in 0--0.20 g/L with A570 at pH of 4.5 was a good linear y= 5.595x-l-0.056（R2=0. 991 2）; For the serine in 0--0. 10 g/L at pH of 5.0, the linear correlation equation is y=10.59x＋0. 023（Rz =0. 998 5） ; For the serine in 0--0.04 g/L with A570 at pH of 6.0, the linear correlation equation is y=37. 388x＋0. 005 2（R2 =0. 991 5）.