荧光共振能量转移体系测定Cr(Ⅵ)的研究

Study on the Determination of Cr(Ⅵ) by Fluorescence Resonance Energy Transfer

在λex/λem=450/512 nm,pH7.23的B-R缓冲溶液存在下,藏红T和钙黄绿素能够发生有效能量转移,而Cr(Ⅵ)的加入使得藏红T和钙黄绿素荧光同时猝灭.利用藏红T-钙黄绿素能量转移荧光法测定痕量的Cr(Ⅵ),提高了测定铬的灵敏度.铬含量在0.25～10μg/mL范围内与钙黄绿素的荧光猝灭程度呈良好的线性关系.最低检出限为9.8 ng/mL;回收率为96.5%～104%.该法用于含铬废水水样中Cr(Ⅵ)的测定,结果满意.

It is found that in the conditions of λex/λem=450/512 nm,pH7.23（B-R）, the effective energy transfer can occur between safranine T （ST） and calcein. And the addition of Cr（Ⅵ） to this system makes the fluorescence intensities of calcein and ST quench simultaneously. So this system of fluorescence resonance energy transfer is applied to the determination of Cr（Ⅵ）. The detection limit of this method is 9.8 ng/mL. The range of determination for Cr（Ⅵ） is 0.25-10μg/mL. The recoveries is 96.5%-104%. The method has been applied to the determination of Cr（Ⅵ） in mixed samples and the wasted water. The results are satisfactory.