聚乙二醇萃取-铬天青S显色分光光度法测定聚烯烃树脂中的铁

Spectrophotometric determination of Fe (Ⅲ) in polyolefin resin with polyethele glycol-ammonium sulfate-aluminon as extractant and chrome azurol S-cetyltrimethy lammonium bromideas as colouring agent.

以聚乙二醇 -硫酸铵 -铝为萃取剂、铬天青S -溴化十六烷基三甲铵为显色剂 ,用分光光度法测定了聚烯烃树脂中的铁。络合物的最大吸收波长为 6 82nm。铁含量在 0～ 5 μg/ 2 5mL范围内符合比尔定律。摩尔吸光系数ε =5 .5× 10 4L·mol-1·cm-1,相关系数r=0 .9997。人工合成样品的平均回收率为 10 1.3% ,RSD为 0 .98%。用该方法测定了聚乙烯树脂和聚丙烯树脂中的铁 ,其RSD分别为 1.3%和 0 .76 % ,加标回收率分别为 10 0 .0 %和10 1.2 %。实验证明 ,该方法具有灵敏度高、选择性好、对环境无污染的特点。

Fe (Ⅲ) in polyolefin resin has been determined by spectrophotometry using chrome azurol S -cetyltrimethy lammonium bromide as colouring sytem after extraction by polyethele glycol-ammonium sulfate-aluminon reagent. The maximum absorption wavelength of the complex is 682nm. Beer's law is obeyed when Fe (Ⅲ) content is in the range of 0～5μg/25mL. ε=5.5×10 4 L·mol -1·cm -1, r=0.9997. The average recovery of synthetic samples is 101.3% with the RSD of 0.98%. Fe (Ⅲ) in polyethylene and polypropylene was determined, the RSD was 1.3% and 0.76%, and the recovery of standard addition was 100% and 101.2%, respectively. The method is highly sensitive and selective and does not contaminate the environment.