以鞣花酸为荧光探针的水体中二/三价铁离子的检测

Detection of Ferrous/Ferric Ions in Aqueous Phase Using Ellagic Acid as Fluorescent Probe

建立了鞣花酸(EA)测定痕量Fe^(2+)、Fe^(3+)的荧光分析法,并讨论了常见金属离子、甲醇体积分数以及pH值对Fe^(2+)、Fe^(3+)定量检测的影响。实验发现,Fe^(2+)、Fe^(3+)在浓度0.08～1.1μmol/L范围内与EA的荧光猝灭程度呈良好的线性关系,检出限分别为72、63 nmol/L。同时发现酒石酸二铵对Fe^(3+)的掩蔽效果良好。通过Job?s plot得到EA与Fe^(2+)及Fe^(3+)的配位比分别为1∶3和1∶2。采用所建立的方法对自来水与珠江水中的Fe^(2+)、Fe^(3+)进行测定,其加标回收率为81.0%～116%。

A fluorescent analytical method for the detection of trace Fe 2+ and Fe 3+ in water was established using ellagic acid (EA ) as fluorescent probe.The effects of common metal ions,methanol concentration and pH value of media on the quantitative detection of Fe 2+ or Fe 3+ were investigated in detail.Results illustrated that a good linear relationship between the flourescence quenching and the concentrations of Fe 2+ and Fe 3+ was obtained within the range of 0.08-1.1 μmol/L with the detection limits of 72 nmol/L and 63 nmol/L,respectively.Meanwhile,Fe ^2+ could be detected accurately without significant interference using 10 mmol/L ammonium tartrate to mask Fe ^3+.In addition,the Job s plot analysis showed that the coordination ratios for EA to Fe ^2+ or Fe^ 3+ were 1 ∶ 3 and 1 ∶ 2 ,respectively.The established method was used in the detection of Fe^ 2+ and Fe^ 3+ in tap water and Zhujiang River water with average recoveries of 81.0 %-116 %.