Abstract: The determination of micro-cooper in crude oil samples by spectrophotometer with chrome azurol S(CAS) as a colored indicator has been developed. The cineration of samples and measuring conditions were studied. After samples burning to ashes at 650 ℃ for at least 4.5 h, Cu in the ash was dissolute by HNO3 solution to separate interference ions. The molar absorption coefficient ε610 nm is 8.32×104 L/(mol•cm). The linear range is between 0～8 μg. The recovery rate of the artificial synthetic sample is 98.04%, and the actual crude oil was analyzed with RSD of the results 4.11%. This method offers the advantages such as good accuracy, ease of operation, no need for separation and high sensitivity. 

Key words: CAS, Copper, Crude oil, Spectrophotometry

摘要： 以铬天青S为显色剂，用分光光度法测定原油中的微量铜，并考察了样品灰化条件和测定条件。在650 ℃将样品灰化4.5 h以上条件下，用HNO3溶液溶解灰分中的铜，使干扰离子与铜分离。在波长610 nm、表观摩尔吸光系数ε=8.32×104 L/（mol•cm）,其线性范围为0～8 μg,合成样回收率98.04 %，原油测定结果的相对标准偏差4.11%，结果表明,该方法准确、简便、不需分离、灵敏度高。

关键词: 铬天青, 铜, 原油, 分光光度法