摘要: |
热液流体中溶解态铁是海水原位测量的重要参数之一。本研究采用Ferene分光光度法, 搭建流动注射分析系统, 优化进样条件、显色条件, 实现了热液流体中溶解态铁的在线测定。结果表明, 测定Fe(II)时, Ferene、缓冲液浓度分别为8×10-3、0.4mol/L, Ferene、样品流速分别为0.8、0.6mL/min, 显色盘管长度为40cm时, 方法的灵敏度、检测限最佳; 测定Fe(III)时, Ferene、缓冲液、抗坏血酸浓度分别为1×10-2、0.5、0.01mol/L, Ferene/抗坏血酸、样品流速均为1.0mL/min, 还原、显色盘管长度均为40cm时, 方法的灵敏度、检测限最佳。最佳实验条件下, Fe(II)、Fe(III)在0.2~10μmol/L和0.5~16μmol/L范围内, 工作曲线回归方程分别为A=0.0834C+0.0564(μmol/L, n=8, R2=0.997)和A=0.0478C+0.0423(μmol/L, n=8, R2=0.997)。Fe(II)、Fe(III)检测限分别为24、39 nmol/L, 相对标准偏差分别为0.8%、1.2%(n=10), 加标回收率为97.9%~103.0%。共存离子实验表明, 流体中的Na+、Mn2+、Cu2+、Cu+不会对测量造成干扰。 |
关键词: 溶解态铁 Ferene 流动注射分析 分光光度法 热液流体 |
DOI:10.11759/hykx20150629002 |
分类号: |
基金项目:国家自然科学基金项目(41306103); 国家重点基础研究973项目课题 (2015CB755901); 海洋公益性行业专项经费资助项目(201405036) |
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Ferene method flow injection analysis as optimized in situ analysis of dissolved iron in marine waters |
WANG Hong-liang,LIU Bao-hua,DING Zhong-jun,YU Kai-ben
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Abstract: |
In this study, we adapted and optimized the ferrozine method flow injection analysis to perform an in situ analysis of dissolved iron. Optimal conditions were achieved for Fe(II) when the Ferene reagent (8 × 10-3 mol/L in a 0.4-mol/L acetic/acetate buffer) was flowing at 0.8 mL/min, the sample flow rate was 0.6 mL, and the reaction coil length was 40 cm. Moreover, optimal conditions were obtained for Fe(III) when the Ferene reagent (1 ×10-2 mol/L in a 0.5-mol/L acetic/acetate buffer), the ascorbic acid reducing solution (0.01 mol/L), and the sample were flowing at 1.0 mL/min, and the length of the reaction and reduction coils were 40 cm. Under these conditions, the calibration curves were A = 0.0834 C + 0.0564(μmol/L, n = 8, R2 = 0.997) for Fe(II) and A = 0.0478 C + 0.0423 (μmol/L, n = 8, R2 = 0.997) for Fe(III). The limits of detection and relative standard deviations were 24 nmol/L, 0.8% (n = 10) for Fe(II) and 39 nmol/L, 1.2% (n = 10) for Fe(III). The recovery was in the range 97.9%?103.0%. The results showed that, using this method, there was no significant interference for Na+, Cu2+, Mn2+, and Cu+. |
Key words: Dissolved iron Ferene Flow injection analysis Spectrophotometry Hydrothermal fluid |