分光光度法测定石化产品中微量铁

以5-溴-2-吡啶偶氮-5-二乙氨基酚/异辛基酚聚氧乙烯醚为显色体系,用分光光度法在746 nm波长处测定了氧化铝载体、重整催化剂、聚氯乙烯及丁苯橡胶中的微量铁。对测定条件、线性范围进行了考察。人工合成试样回收率为100.9%,铝合金标样测定结果的相对误差小于±2.0%。试样测定结果的相对标准偏差小于2.2%,加标回收率为100.8%～102.7%。摩尔吸收系数2.8×10~4L/(mol·cm)。方法的选择性高,不必萃取分离干扰离子或加掩蔽剂,可直接测定。准确简便。

SPECTROPHOTOMETRIC DETERMINATION OF TRACE IRON IN PETROCHEMICAL PRODUCTS

2-(5-Bromo-2-pyridylazo)-5-diethylaminophenol/isooctylphenolpolyethoxylate(5-Br- PADAP-TritonX-100)was used as color developer to determine trace iron in Al_2O_3 supporter,refor- ming catalyst,polyvinyl chloride and styrene-butadiene rubber by spectrophotometry at 746 nm wave- length.The determination conditions and linear range of this method were studied.The results show that the average recovery of the synthetic samples is 100.9%;the relative errors of determination re- sults for standard samples of aluminium alloy are less than±2.0%;the relative standard deviations of determination of samples are less than 2.2%;the recoveries of standard added samples are 100.8%- 102.7%.The molar absorbility is 2.8×10~4 L/(mol·cm).The selectivity of this method is high,and trace iron in samples could be directly determined without extraction and seperateion from interfering ions or addition of masking agent,thus it is an accurate and convenient method.