Identification Of Marine Oil Spills By Chemometrics Based On Characteristics Of Nickel And Vanadium On Oil Products

The identification of crude oil types is a very important link in offshore oil spill accidents.At present,there are many researches on the species identification of offshore oil spill,but most of them are qualitative analysis of the components in crude oil,and there are few quantitative researches on them.Based on the theoretical basis of stoichiometry,this paper transforms the qualitative analysis of the characteristics of nickel and vanadium in crude oil into quantitative analysis with a view to providing a new means for the identification of oil spill.This paper studied eight Middle East crude oil and eight kinds of non-middle east crude oil,the contents of Ni and V of crude oil samples were measured by atomic absorption spectrophotometer.The effects of weathering on the properties of nickel and vanadium in crude oil are investigated through short-term weathering experiments.Similarity analysis was performed on 16 crude samples,and based on the analysis conclusion establishing the Logistic regression model and Fisher discriminant function for classification of crude oil samples from the Middle East and non-middle east region.The RSD value of each crude sample is less than 6%after the short-term weathering test,this indicates that the content of nickel and vanadium in crude oil is not affected by weathering conditions.It has strong weathering resistance because ofthe properties of nickel and vanadium are stable.Therefore,the ratio of nickel to vanadium can be an important technical index for the identification of offshore oil spill.Based on the ratio of Ni,V and Ni/V as eigenvectors,the similarity analysis of 16 crude oil samples was carried out.The results show that the similarity between Middle East and non-middle east crude oil is low,so there are obvious differences between the two types of oils,which is provided a theoretical basis for logistic regression model and fisher discriminant function.The logistic regression model and fisher discriminant function established by using Ni,V and Ni/V ratio as parameters have high discriminant ability to oil species.The experimental results show that the accuracy of Logistic regression model was 93.8%and 89.5%respectively;Fisher discriminant function was 87.5%and 84.2%respectively for weathering and document crude oil.It can be inferred that Logistic regression model is better than Fisher discriminant function for the identification of oil spill.The Logistic regression model and Fisher discriminant function can identify the unweathered oil samples,and can also identify the weathered oil samples,both can provide scientific technical support for the identification of offshore oil spill.