沙枣皮色素荧光光度法测定铁(Ⅲ)
Fluorophotometric Determination of Fe(Ⅲ) with the Pigment of Peel of Elaeagnus Angustifolia as Fluorescence Probe
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摘要: 沙枣皮经用水超声浸取可得呈黄色的沙枣皮色素提取液.将此提取液经装有AB-8吸附树脂的固相萃取柱净化,用乙醇-水(7+3)溶液作淋洗液从柱上洗脱该色素,并用真空蒸发得到具有荧光性质的色素溶液.由于铁(Ⅲ)与沙枣皮色素的结合反应,引起沙枣皮色素荧光淬灭,且其荧光淬灭程度与铁(Ⅲ)浓度在2.0×10-6~6.0×10-5mol·L-1范围内呈线性关系.据此提出了以沙枣皮色素为探针测定铁(Ⅲ)的荧光光度法.方法的检出限(3S/N)为1.0×10-7mol·L-1.用标准加入法对方法的回收率作了试验,测得回收率在99.5%~101.5%之间.Abstract: Peel of elaeagnus angustifolia was extracted ultrasonically with water to obtain a yellow colored extract of pigment of peel of the above mentioned plant.The extract was then purified by passing through SPE column filled with AB-8 adsorptive resin and eluting with C2H5OH-H2O mixture (7+3).The ethanolic eluate was further concentrated by vacuum-evaporation,to obtain the fluorescent pigment solution.It was found that the fluorescence of the pigment solution was quenched by its combination with Fe(Ⅲ) ion,and that the magnitude of decrease in fluorescence intensity kept linear relationship with concentration of Fe(Ⅲ) in the range of 2.0×10-6-6.0×10-5mol·L-1.Based on these facts,a fluorophotometric method for determination of Fe(Ⅲ) using this pigment as fluorescence probe was proposed.Detection limit (3S/N) of the method was found to be 1.0×10-7mol·L-1.Recovery of the method was tested by the standard addition method,giving values of recovery in the range of 99.5%-101.5%.