Effect of oil spill dispersant on the oil fingerprints investigated by variance analysis

6 kinds of crude oil and oil spill dispersant (referred to as dispersant) mixture samples as the research object were obtained by 2 kinds of crude oils and 3 kinds of dispersants in this paper.The effect of the type and the relative content of dispersant on the oil fingerprint (alkanes diagnostic ratio) was investigated by mean of variance analysis.First of all,the raw data was successively tested by one-sample nonparametric Kolmogorov-Smirnov(K-S) test and Cochran maximum variance test.And then the diagnosis ratios not suitable for variance analysis were excluded.Finally,the remaining data meet the requirements was analyzed by mean of variance analysis.This study found that some of the diagnostic ratios were affected by dispersants no matter what they were,and some of the diagnostic ratios were affected significantly or not significantly with different types of dispersants.This indicated that the diagnostic ratios in this study were affected by the type and the relative content of dispersant,and the effect of dispersant should be considered in oil fingerprint identification.