荷移分光光度法测定缬氨酸

Determination of Valine by Charge-Transfer Spectrophotometry

用分光光度法研究缬氨酸与7,7,8,8-四氰基对苯醌二甲叉(TCNQ)的荷移反应。确定以pH=9.2的三酸缓冲溶液为介质,在50℃的水浴中加热30min,形成稳定的络合物,其λ_(max)=417nm,表观摩尔吸光系数ε=7.8×10~3L·mol^(-1)·cm^(-1),在1—9μg/mL的范围内符合比耳定律,回收率在96.7%—102.7%,相对标准偏差小于2.9%。

The charge-transfer reaction of valine with 7,7,8,8-tetracyanoquinodimethane （TCNQ） was investigated by spectrophotometry.The experimental conditions were optimized and a new method for determination of valine has been developed.The stable charge-transfer complex was formed in Britton-Robinson buffer solution（pH=9.2） by heating in 50＇C water bath for 30min.The apparent molar absorptivity of the complexεwas determined for 7.8×10~3L · mol^（-1） · cm^（-1） at 417nm.Beer＇s Law was obeyed in the range of 1—9μg/mL of valine.The recovery was 96.7%—102.7%,and the relative standard deviation was less than 2.9%.