低压离子色谱分离-化学发光在线检测过渡金属离子

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

研究了低压离子色谱 (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。利用此法测定了维生素B12 中Co2 + 以及人发样中Cu2 + ,Mn2 + ,Cr3 + ,Co2 + 和Fe2 + 等离子的含量 ,结果与原子吸收法所测值基本吻合。

The separation and determination of five transitional metal ions, Co 2+ , Cu 2+ , Mn 2+ , Fe 2+ and Cr 3+ by low pressure ion chromatography with chemiluminescence detection were investigated for the first time. The separation was carried out on a C 3 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 H 2O 2 M n + 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 H 2O 2 and 0 020 mol·L -1 NaOH, the linear ranges (mg·L -1 ) for Co 2+ , Cu 2+ , Mn 2+ , Fe 2+ and Cr 3+ were 0 001-0 1, 0 1-6, 0 06-4, 0 03-5 and 0 025-1 respectively; the detection limit (μg·L -1 ) for Co 2+ , Cu 2+ , Mn 2+ , Fe 2+ and Cr 3+ were 0 85, 85, 42, 21 and 20. The present method is simple, rapid, accurate and has been successfully applied to detect Co 2+ in vitamin B 12 and Co 2+ , Cu 2+ , Mn 2+ , Fe 2+ and Cr 3+ in human hair sample with satisfactory results, which were in good agreement with those from atomic absorption spectrometry.