曙红Y-藏红T能量转移荧光猝灭法测定痕量锰

Determination of trace manganese by eosine Y-safranine T energy transfer fluorescence quenching method

在pH 6.0介质中,十二烷基苯磺酸钠(SDBS)作用下,曙红Y-藏红T能发生有效的能量转移,使藏红T荧光增强,二价锰的加入使藏红T在577nm处发生荧光猝灭,其荧光猝灭程度与锰的含量呈线性关系,由此建立了能量转移荧光测定痕量锰的新方法。试验探讨了体系的最佳条件:1.0×10-6 mol/L曙红Y溶液0.5mL、1.0×10-5 mol/L藏红T溶液4.0mL、1.0×10-3 mol/L SDBS溶液0.3mL,40℃恒温水浴中水浴加热4min。在优化条件下,锰(Ⅱ)质量浓度在0.4×10-8~6.0×10-8 mol/L范围内与荧光猝灭程度呈线性响应,方法检出限为6.0×10-9 mol/L。将该体系应用于茶叶和土壤样品中锰的测定,相对标准偏差(RSD,n=11)小于5%,回收率为93.8%~95.6%。

The effective energy transfer of eosine Y-safranine T occurred in medium at pH 6.0 in presence of sodium dodecyl benzene sulfonate(SDBS),leading to the fluorescence enhancement of safranine T.The addition of manganese(II)resulted in the fluorescence quenching of safranine T at 577 nm.The fluorescence quenching extent showed linear relationship with the content of manganese(II).On the basis of this phenomenon,a new method for determination of trace manganese by energy transfer fluorescence quenching was established.The following optimum conditions of this system were obtained:0.5 mL of 1.0×10-6 mol/L eosine Y solution,4.0 mL of 1.0×10-5 mol/L safranine T solution,0.3 mL of 1.0×10-3 mol/L SDBS solution,heating in thermostatic water bath at 40℃for 4 min.Under the optimized conditions,the mass concentration of manganese(II)in range of 0.4×10-8-6.0×10-8 mol/L showed linear relationship with the fluorescence quenching extent.The detection limit of method was 6.0×10-9 mol/L.The proposed system was applied for determination of manganese in tea and soil samples,and the relative standard deviations(RSD,n=11)were less than 5%,the recoveries were 93.8%-95.6%.