海水石油类分析的影响因素

石油类是衡量海水水质的重要指标,海洋石油的首要污染源是原油泄漏,因此海水石油类的具体成分与原油成分基本一致,主要为弱极性的烷烃、环烷烃和芳香烃。在3种国标分析方法中,紫外分光光度法的应用最为广泛。采用该法分析时,建议统一选择HJ油标准作为标准溶液,透光率90%的正己烷作为萃取剂,标准曲线斜率在斜率控制图内的上下辅助限之内;萃取过程中调节水样p H值2,人工萃取时间120 s,萃取后不能立即分析时,在5℃冰箱内保存不超过2周。

Influencing Factors on the Analysis of Marine Petroleum Oils

Petroleum oils is an important indicator of seawater quality.Its primary pollution source is oil leakage, so the specific component is similar to that of the crude oil, which includes weak polar alkanes, cycloalkanes and aromatic compounds.There are three national standard methods to determine petroleum oils concentration, and UV spectrophotometry is the most commonly used. When using this method, HJ oil is suggested as the standard solution and n-hexane as the extraction reagent.Transmittance of the n-hexane must be larger than 90%.In the slope control chart, the slope must be controlled within its auxiliary limits.Before extrac-tion, marine samples must be adjust pH<2, and the artificial extraction time must be more than 120 s.The extracted liquid must be stored in the refrigerator at 5 ℃for no more than two weeks if it cannot be analyzed immediately.