荧光光度法测定环境水样中镁的含量——基于与邻菲啰啉生成络合物而产生的荧光增敏作用

Fluorophotometric Determination of Magnesium in Environmental Water Samples Based on Its Sensitization of Fluorescence of o-Phenanthroline Due to Complex Formation

在pH10．0的缓冲介质中，以235nm和360nm为发射波长测定时，邻菲口罗啉试剂的荧光因与镁（Ⅱ）反应生成了络合物而得到增敏，其增敏的程度（△F）与镁（Ⅱ）的质量浓度之间在0．1～2．0mg·L^-1范围内呈线性关系。此反应的检出限（3s／b）为0．038mg·L^-1。应用此方法测定了3种不同来源的水样中镁的含量，测定值的相对标准偏差（n=6）在1．3％～1．6％之间。在此样品的基础上用标准加入法做回收试验，测得回收率在98％～103％之间。

In a buffer medium of pH 10, fluorescence of the reagent o-phenanthroline was enhanced due to the formation of a complex with Mg^2＋ ion, when measured at the wavelengths of 235 nm （λex） and 360 nm （λem）. The magnitude of increase in fluorescence intensity （△F） was found to keep linear relationship with concentration of Mg^2＋ ion in the range from 0. 1--2. 0 mg ·L^-1. Detection limit （3s/b） found for the method was 0. 038 mg ·L^-1. Three water samples of different sources were analyzed for their magnesium contents by this method, values of RSD＇s （n=6） found were in the range from 1.3%--1.6%. Test for recovery was made, giving values of recovery ranged from 98%--103%.