低压离子分离-化学发光在线检测过渡金属离子

 研究了低压离子 (LPIC)分离 柱后鲁米诺化学发光 (CL)检测方法 ,并分离测定了Cu2 + ,Co2 + ,Cr3 + ,Fe2 + ,Mn2 + 等 5种过渡金属离子。以草酸 柠檬酸混合溶液作为洗脱液 ,Luminol H2 O2 Mn + 作为化学发光检测体系 ,对过渡金属离子进行在线检测。测定的线性范围分别为 (mg·L-1) :Co2 + ,0 0 0 1～ 0 .1;Cu2 + ,0 1～ 6 ;Mn2 + ,0 0 6～ 4 ;Fe2 + ,0 0 3～ 5 ;Cr3 + ,0 0 2 5～ 1。检测限分别为 (μg·L-1) :Co2 + ,0 85 ;Cu2 + ,85 ;Mn2 + ,4 2 ;Fe2 + ,2 1;Cr3 + ,2 0。

On-Line Determination of Transitional Metal Ions by Low-PressureIon Chromatography with Chemiluminescence Detection

The separation and determination of five transitional metal ions, Co2+, Cu2+, Mn2+, Fe2+ and Cr3+ by low-pressure ion chromatography with chemiluminescence detection were investigated for the first time. The separation was carried out on a C3 ion chromatographic column by using a step gradient elution with the mobile phase of oxalic acid-citric acid solution. The five transitional metal ions could be separated simultaneously. Luminol-H2O2-Mn+ system was used as the flow injection chemiluminescence analytical system. Under the optimum conditions with 0.5 mmol.L-1 luminol, 0.05 mol.L-1 H2O2 and 0.020 mol.L-1 NaOH, the linear ranges (mg.L-1) for Co2+, Cu2+, Mn2+, Fe2+ and Cr3+ were 0.001-0.1, 0.1-6, 0.06-4, 0.03-5 and 0.025-1 respectively; the detection limit (microgram.L-1) for Co2+, Cu2+, Mn2+, Fe2+ and Cr3+ were 0.85, 85, 42, 21 and 20. The present method is simple, rapid, accurate and has been successfully applied to detect Co2+ in vitamin B12 and Co2+, Cu2+, Mn2+, Fe2+ and Cr3+ in human hair sample with satisfactory results, which were in good agreement with those from atomic absorption spectrometry.