基于钙黄绿素－臧红T荧光共振能量转移检测六偏磷酸钠

在pH8．5的Tris－HCl缓冲溶液中，钙黄绿素作为能量供体（D）可以与藏红T受体（A）发生有效的荧光共振能量转移（FRET），但加入六偏磷酸钠（SHMP）后，因其与受体发生静电作用破坏了该能量转移体系，使得荧光供体钙黄绿素荧光强度的增加（△FD）与受体藏红T荧光强度的降低（△FA）的比值（△FD／△R）-9SHMP浓度（csHMP）呈良好的线性关系．基于此，建立了一种检测六偏磷酸盐的新方法．在优化条件下，该方法的检测范围为3．0×10^-6-1．0×10^-5mol／L，对6．0×10拍mol／L的六偏磷酸盐连续平行测定11次，其相对标准偏差（RSD）为3．1％．该方法具有选择性好、操作简单和检测速度快等优点，已成功应用于饮料中六偏磷酸钠的分析检测．

Determination of sodium hexametaphosphate based on the fluorescence resonance energy transfer between calcein and safranine T

In a medium of tris-HC1 buffer （pH 8.5）, calcein （donor） can react with safranine T （acceptor） efficiently to produce fluorescence resonance energy transfer （FRET）. However, the addition of sodium hexametaphosphate （SHMP） destroyed the FRET system because of the electrostatic interaction between SHMP and the acceptor, which makes fluorescence change ratio between the increased fluorescence intensity of calcein and the reduced fluorescence of ST （AFo/AFA） has a good linear correlated with the concentration of SHMP. Based on the phenomena, a novel rapid FRET method for determination of sodium hexametaphosphate was developed. Under the optimized conditions, the linear range is 3.0x10-6-1.0~lffs mol/L, and the relative standard deviation （RSD） is 3.1% for determination of sodium hexametaphosphat （c = 6.0~10 6, n = 11）. The proposed method is of high selectivity, simple to operate and rapid detection, and is successfully applied to determine the concentration of SHMP in drink samples.