流动注射-化学发光法测定海水中的痕量Fe(Ⅱ)

Flow injectionluminol-based chemiluminescence method as optimized in Fe(Ⅱ) analysis of seawater

摘要: 本文以MOPS3-（N-吗啉）丙磺酸为缓冲溶液抑制Fe（Ⅱ）的氧化，利用luminol化学发光法，研究了pH、MOPS加入量、luminol浓度、试剂流速、信号积分时间等参数在Fe（Ⅱ）测定中对测量灵敏度的影响。结果表明，MOPS的加入能显著增大发光信号。测定中国近海中痕量Fe（Ⅱ）的最佳实验条件为：缓冲液pH为7.2、MOPS添加浓度2 mmol/L、luminol浓度1 mmol/L、试剂流速3 mL/min、积分时间200 ms。本文以东海水为空白海水，测得方法检出限为116 pmol/L，测定线性范围为0.116~150 nmol/L。

Abstract: The determination method of dissolved Fe (Ⅱ) in seawater was studied based on luminol chemiluminescence in this paper.MOPS (3-(N-morpholino) propanesulfonic acid) was used as buffer to suppress Fe (Ⅱ) oxidation, at the same time, factors that may influence the sensitivity of Fe (Ⅱ) determination, such as the concentrations of MOPS and luminol, buffering pH, pump rate and integration time were studied.It demonstrated that the sensitivity was greatly enhanced by the addition of MOPS.In addition, optional conditions of pH=7.2, 2 mmol/L MOPS, 1 mmol/L luminol, 3 mL/min pump rate and 200 ms integration time, are used to determine trace amount Fe (Ⅱ) in the coastal seawater of China.Using the East China Sea water as blank water, the limit of detection is 116 pmol/L Fe (Ⅱ), and the measurement range is 0.116~150 nmol/L.