In the pH 4. 7 of acetic acid sodium buffer system, Fe( III ) and anthocyanins which extracted from the red cabbage and purificatied to form stable complexes, this paper studies the complex absorption spectrum and molecule fluorescence spectrum, and we establish a new method of the quantitative determination of Fe( III). In the presence of cationic surfactant CTMAB, anthocyanins that used the XAD-2 macroporous resin to purify colored with Fe( II) in acetic acid sodium buffer system. The maximum absorption wavelength of complex was 630 nm. The molar absorption coefficient of complex is 6. 16×l03 L · mol-1 · cm-1. There was a well linear relationship between absorbance and Fe( III) of which contents is in the range of 2-10 mg · L-1, correlation coefficient R2= 0. 9995. A quantitative solution detection limit of 0. 91 μg · mL-1 was obtained. This method can be used to determine the country rock ore standard sample( super mafic rocks DZE-2) ,the relative standard deviation is 1. 65%. Excellent agreement between the experimental values and the certified concentrations and the optimum recoveries of 93. 8%-105% by addition of the standard solution in the rock reference materials was obtained. It was found that the fluorescence of Anthocyanin solution which has fluorescence property was quenched by its combination with Fe( III).%在pH4.7的乙酸-乙酸钠缓冲体系中,Fe(Ⅲ)能与自紫甘蓝中提取纯化的花青素形成稳定的络合物,本文研究了该络合物的吸收光谱和分子荧光光谱,建立了一种测定Fe(Ⅲ)的方法.在阳离子表面活性剂CT-MAB存在下,经过XAD-2大孔树脂纯化后的花青素与Fe(Ⅲ)在乙酸-乙酸钠缓冲体系中显色,络合物最大吸收波长630 nm,摩尔吸光系数6.16×103 L·mol-1·cm-1,Fe(Ⅲ)含量在2-10 mg·L-1范围内与吸光度呈良好的线性关系,相关系数R2=0.9995,定量检出限0.91 μg-mL-1.该方法用于测定国家岩矿标准样品(超基性岩DZE-2),相对标准偏差1.65％,岩矿样品加标回收率在93.8％～ 105％.花青素溶液具有荧光性质,与Fe(Ⅲ)反应可引起花青素溶液荧光猝灭.
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