水杨醛缩-5-碘-8-氨基喹啉萃取光度法测定水中痕量铝

研究了水杨醛缩-5-碘-8-氨基喹啉(SAIAQ)与铝的显色反应,并建立了水中痕量铝的分光光度测定方法。在pH 4.0的HAc-NaAc缓冲溶液中,在乳化剂OP-10存在下,SAIAQ与铝反应生成组成比为2比1稳定配合物。配合物最大吸收波长为450 nm,表观摩尔吸光系数为2.75×10⁵ L·mol^-1·cm^-1,铝质量浓度在0～260 μg/L的范围内符合比尔定律。采用CCl₄萃取能使铝与水中大量常见元素分离。方法已用于水中痕量铝的测定,测定结果与催化光度法的测定结果相符。6次测定管网水样品中铝的相对标准偏差小于1%,加标回收率在98.6%～104.0%之间。

Determination of trace aluminum in water by extraction spectrophotometry with salicylidene-5-iodo-8-aminoquinoline

The chromogenic reaction of salicylidene-5-iodo-8 aminoquinoline (SAIAQ) with aluminum was studied, and a spectrophotometry for the determination of trace aluminum in water was established. In the medium of HAc-NaAc buffer solution at pH 4.0, SAIAQ could react with aluminum to form a stable complex at a ratio of 2∶1 in the presence of emulsifier OP-10. The maximum absorption wavelength of the complex located at 450 nm with a molar absorptivity of 2.75×10⁵ L·mol^-1·cm^-1. Beer's law was obeyed in the range of 0-260 μg/L for aluminum. Aluminum in water could be separated from large amounts of common elements by means of CCl₄ extraction. This method has been applied to the determination of trace aluminum in water,whose results were in good agreement with those obtained by catalytic photometric method. The relative standard deviation (RSD) for six determination of Al in tap water was less than 1%. The standard addition recovery was 98.6%-104.0%.