流动注射分光光度法测定油田水中的微量碘

I₂与Br^-可以形成[I₂ Br]^-配阴离子[I₂ Br]^-可和罗丹明B进一步缔合形成三元缔合物。I₂^-溴化钾-罗丹明B三元缔合体系具有高灵敏显色特性，形成的有色产物在585 nm波长处有最大吸收。研究发现，在酸性介质中，Ce(W)可以将I一快速氧化为I₂，基于此建立了流动注射一分光光度法测定油田水中微量碘的新方法。在CTMAB的增敏作用下，对体系和流动注射系统诸参数进行了优化，碘离子浓度在0.050 0 -1.00 m酬L范围内呈线性关系，线性方程为:H(mV) -76.6 c(mg/L) -2.933 3，相关系数r = 0. 999 6，最低检出限为0. 020 mg/L，相对标准偏差RSD =0.85%(n=11)该方法灵敏、快速、操作简便，用于油田水样品中碘的测定，结果满意。

SPECTOPI30TOMETRIC FLOW-INJECTION ANALY-SIS ON TRACE I-IN RESERVOIR WATER

In the present method, a new , simple and rapid spectopho-tometric flow injection technique for the accuracy and determina-lion of I^-in reservoir water has been developed. The method isbased on the decrease of absorbance intensity of rhodamine Bdue to the complexation with[I₂Br]^-，I^-can be selectively ox-idated to form I₂ by Ce(Ⅳ)in acidic medium and Iz reacts withBr^-to form[I₂Br]^-，At this moment, some changes of the so-lotion's color takes place. It is found useful for sensitivity in CT-MAB media. The absorption peak of the complexation, which isincreased linearly By addition of I^-，occurs at 585 nm. Optimi-zation of chemical and flow injection variables has been made.Under the optimized conditions，the calibration curve obtained islinear over the range 0. 0500~1. 00 mg/L, the linear equationis H(mV) =76.6c(mg/L)-2. 933 3，r=0. 999 6，the de-section limit is 0. 020 mg/L, and the precision(RSD=0. 85 %，n=11 )is found quite satisfactory. This method has good sensi-tivity and selectivity. Application of the method to the analysison I^-in reservoir water resulted a good agreement between theexpected and found values.