流动注射-分光光度法测定海水中微量铜

Flow-injection spectrophotometric determination of micro copper in seawater

研究了以二苯碳酰二肼（DPC）为显色剂，NaCl溶液为反应介质，溴化十六烷基吡啶（CPB）、OP乳化剂为增敏剂测定Cu^2＋的分光光度体系，建立了流动注射分光光度测定海水中痕量Cu^2＋的新方法。对流动注射分析条件进行了优化，确定了检测波长为500nm。在最优条件下，方法的检出限为0．003mg／L，Cu^2＋的质量浓度在0．005～0．050mg／L范围内，峰高测量值与浓度呈良好线性关系，线性方程为：H（mV）=0．6161＋0．1752×10^-3ρ（mg／L），相关系数r=0．9988。对含量为0．020mg／L的Cu^2＋标准溶液进行了11次平行测定，其相对标准偏差（RSD）为1．0％。经使用掩蔽剂可有效地消除其它共存元素的干扰，方法用于模拟海水、海水等高盐体系中Cu^2＋的测定，结果与石墨炉原子吸收分光光度法的结果相一致。

With diphenyl carbazide （DPC） as coloring agent, NaCl solution as reaction medium, and hexadecylpyridinium bromide （CPB） and OP emulsifier as sensitizing agent, a novel method for the determination of micro Cu^2＋ in seawater by flow-injection spectrophotometry was developed. The experimental conditions of flow-injection analysis were optimized, and the detection wavelength was 500 nm. Under optimum conditions, the detection limit of the method was 0. 003 mg/L. The peak height showed good linearity with the concentration of Cu^2＋ in the range of 0. 005--0. 050 mg/L. The linear equation was H（mV）=0. 616 1＋0. 175 2×10^-3 ρ（mg/L） with r = 0. 998 8. The relative standard deviation was 1.0 % （n=11） for determination of 0. 020 mg/L Cu^2＋ in the standard solution. The interferences of other coexisting elements could be effectively eliminated with masking agent. The proposed method had been applied to the determination of trace Cu^2＋ in simulated seawater and actual seawater. The results were in good agreement with those obtained by graphite furnace atomic absorption spectrophotometry （GF-AAS）.