含锌工业用水中痕量总铁测定的分光光度法

Spectrophotometry for the determination of trace iron in industrial water containing Zn^(2+)

建立了一种适用于含锌工业用水中痕量总铁测定的分光光度方法。在p H=9.00的条件下,用紫脲酸铵掩蔽Zn2+,用邻苯二酚紫与Fe2+反应生成蓝色络合物,以预先用邻菲罗啉掩蔽了Fe2+的显色体系为参比,605 nm处的吸光度与样品溶液中0.02~0.6 mg/L的Fe2+呈良好的线性关系,灵敏度约为邻菲罗啉法的5倍,检出限0.012 mg/L,加标回收率97.0%~100%,相对标准偏差1.16%。方法具有较高的灵敏度、准确度和重现性。

A spectrophotometry method suitable for the determination of trace total iron in industrial water containing Zn2＋ has been established. In the buffer solution when pH=9.00, murexide is used for masking Zn2＋ and the reaction of pyrocatechol violet with Fe2＋ forms a blue complex. Taking the chromagenic system whose Fe2＋ has been masked by phenanthroline as reference solution,it is found that there is a good linear relationship between the absorbance of 605 nm and Fe2＋ whose concentration is in the range of 0.02-0.6 mg/L in the sample solution. Meanwhile,the sensitivity of pyrocatechol violet spectrophotometry is about 5 times as much as that of phenanthroline spectrophotometry, detection limit is 0.012 mg/L,standard recovery rates are from 97% to 100% ,and relative standard deviation is 1.16%. The results indicate that the method has superior sensitivity, accuracy and reproducibility.