【摘要】 采用电渗泵顺序注射 -分光光度法对水中痕量Cr(Ⅵ )进行了测定 ,方法通过改变电渗泵流量、流动方向及阀注入时间 ,实现试剂和样品的定量注入和反应时间的控制 ;泵工作电压为直流200V ,流量为0.45mL/min ,显色剂采用二苯碳酰二肼 ,显色剂进样时间为30s,样品进样时间为15s ,反应生成的紫红色配合物在540nm处检测 ;该法线性范围为0.010～1.20mg/LCr(VI) ,检出限为3.4μg/L ;应用该法成功地进行了地表水中Cr(Ⅵ )的测定更多还原

【Abstract】 Sequential injection-spectrophotometry was applied to the determination of trace Cr(Ⅵ) in water. By changing the flow rate and direction of electroosmotic pump as well as the sample injection time, the reagent and analytical sample could be quantitatively injected, and the reaction time could be controlled. Diphenyl carbazide was used as a colour reagent. The analytical conditions were optimized. A pump flow rate of 0.45 mL/min(200 V), a reagent injection time of 30 s, and a sample injection time of 15 s were selected. The produced complex was spectrophotometrically detected at 540 nm. The linear range and detection limit(3σ, n=11) for Cr(Ⅵ) were 0.010～1.20 mg/L and 3.4 μg/L, respectively. The method was successfully applied to the determination of Cr(Ⅵ) in surface water.更多还原