对二甲氨基苯甲醛缩邻氨基苯甲酸与锑(Ⅲ)的荧光猝灭反应及其应用

Fluorescence quenching reaction of 4-dimethylaminobenzaldehyde-anthranilic acid with antimony(Ⅲ)and its application

合成和鉴定了一种新的荧光试剂对二甲氨基苯甲醛缩邻氨基苯甲酸（DBAA）,并研究了DBAA与锑（Ⅲ）的荧光猝灭反应,同时探讨了将其应用于锑（Ⅲ）分析的最佳条件。实验表明,于10mL具塞比色试管中,依次加入0.5mL 1.0×10-6 mol/L DBAA乙醇溶液、2.0mL pH4.00的邻苯二甲酸氢钾缓冲溶液、3.0mL无水乙醇、一定量的锑标准溶液,室温反应20min,于激发波长λex=338nm,发射波长λem=402nm处测定,锑（Ⅲ）的质量浓度在0-60μg/L范围内与其对应的荧光猝灭程度呈良好的线性关系,相关系数为0.997 8,方法检出限为0.2μg/L。实验方法应用于自来水和湖水中痕量锑（Ⅲ）的测定,测定结果与火焰原子吸收光谱法（FAAS）基本一致,相对标准偏差（RSD,n=6）为2.6%-4.3%。

A new fluorescent reagent of 4-dimethylaminobenzaldehyde-anthranilic acid（DBAA）was synthesized and identified.Moreover,the fluorescence quenching reaction of DBAA with antimony（Ⅲ）was investigated,and the optimal conditions for its application for determination of antimony（Ⅲ）were discussed.0.5mL of 1.0×10-6 mol/L DBAA ethanol solution was added to 10 mL colorimetric tube with stopper,then 2.0 mL of potassium hydrogen phthalate buffer solution at pH 4.00,3.0 mL of absolute ethanol and certain amount of antimony standard solution was added successively.After reaction at room temperature for 20 min,the solution was determined at excitation wavelengthλex=338nm and emission wavelengthλem=402nm.The results showed that the mass concentration of antimony（Ⅲ）in range of 0-60μg/L had good linear relationship with its corresponding fluorescence quenching degree.The correlation coefficient was 0.997 8.The detection limit of method was 0.2μg/L.The proposed method was applied to the determination of trace antimony（Ⅲ）in some water samples including tap water and lake water.The results were basically consistent with those obtained by flame atomic absorption spectrometry（FAAS）.The relative standard deviations（RSD,n=6）were between 2.6% and 4.3%.