催化退色光度法测定痕量铁——Fe(Ⅲ)-中性红-H_2O_2体系

• 作 者: 曹永林 陈恕华
• 机 构: 镇江师范专科学校化学系,
• 出 处: 理化检验.化学分册
• 发表日期: 1989年01期
• 关键词: 固定时间法 Fe H_2O_2 催化光度法测定 中性红 过氧化氢氧化 测定范围 非催化反应 比色管 硫酸介质

近几年来,有一些痕量铁的催化光度法测定的报道。我们发现,在稀硫酸介质中,痕量铁(Ⅲ)对过氧化氢氧化中性红的反应有强烈的催化作用。采用固定时间法,催化反应与非催化反应的吸光度之差与铁(Ⅲ)的浓度在一定范围内呈线性关系。由此我们建立了催化退色光度法测定痕量铁的新方法。本方法的灵敏度高,为1×10~(-9)g·ml~(-1),测定范围为0～0.7μg/25ml,重现性较好。本法适于测定食品中的痕量铁。

In recent years there have been some reports of the catalytic spectrophotometric determination of trace amounts of iron. We found that trace iron (III) strongly catalyzes the reaction of hydrogen peroxide with neutral red in dilute sulfuric acid. Using the fixed time method, the difference between the absorbance of the catalytic reaction and the non-catalytic reaction shows a linear relationship with the iron (Ⅲ) concentration within a certain range. Therefore, we established a new catalytic fading spectrophotometric determination of trace iron. The method has high sensitivity of 1 × 10 -9 g · ml -1 and the determination range is 0-0.7 μg / 25 ml, and the reproducibility is good. This method is suitable for the determination of trace amounts of iron in food.