8-羟基喹啉固相萃取光度法测定水样中铁的研究

Study on solid phase extraction and spectrophotometric determination of iron in water with 8-hydroxyquinoline

研究了8-羟基喹啉(8-HQ)与铁 的显色反应,在pH为7.0的醋酸铵缓冲介质中,CTMAB存在下,8-羟基喹啉与铁 反应生成3∶1稳定的蓝紫色络合物,该络合物可被C18固相萃取小柱萃取富集,富集倍数可达100倍.络合物用乙醇洗脱后用光度法测定,λmax=590nm.铁 含量在0～5μg/mL内符合比尔定律,方法用于水样中痕量铁的测定,结果令人满意.

The color reaction of iron (Ⅲ) with 8-hydroxyquinoline was studied.In the presence of pH(7.0) NH_4Cl buffer solution and CTMAB medium,8-hydroxyquinoline reacts with iron(Ⅲ) to form a stable (3∶1) complex.This complex was extracted by Waters C_(18) cartridge.After the enrichment had finished,the retained chelate can be eluted by ethanol.In the measured solution, the molar absorptivity is 7.23×10~3L·mol^(-1)·cm^(-1) at 590nm.Beer's law was obeyed in range of 0～5.0μg/mL.This method can be applied to the determination of iron in water with good results.