浊点萃取-分光光度法测定自来水及酒类样品中的痕量铁

利用非离子表面活性剂TritonX-100在温度高于其浊点时形成相分离行为,建立了浊点萃取-分光光度法测定痕量铁的新方法,探讨优化了以KSCN为显色剂,TritonX-100浊点萃取富集痕量铁的实验条件.研究发现:加入正辛醇可使TritonX-100的浊点降低约30℃,有利于萃取实验的进行;同时,加入的正辛醇与TritonX-100对痕量铁起到了协同萃取作用.在优化了的实验条件下,进行了痕量铁的分析,检出限为0.02mg·L-1,加标回收率为97.4%～101.6%,应用于自来水及酒类样品中痕量铁的测定,结果满意.

Determination of Trace Iron in Water and Wine Samples by Spectrophotometry with Cloud Point Extraction

A new method utilizing non-ionic surfactant of Triton X-100,which can be separated into two phases by heating to its cloud point,was developed to extract trace iron.And the effect of experimental conditions,such as Triton X-100 as surfactant and potassium thiocyanate as complexing agent on cloud point extraction (CPE),was also discussed.The CPE process was improved by reducing the cloud point of the surfactant solution about 30 ℃ with octanol;and the iron was co-extracted by Triton X-100 and octanol.Under the optimal experiment conditions,the detection limit was 0.02 mg·L-1,and the recovery of iron was 97.4%～101.6%.The method has been applied to the determination of trace iron in water and wine samples with satisfactory results.