Study On Rapid Identification Of Oil Fingerprint By ATR-FTIR Combined With GC-FID

With the transportation of large-scale materials and the exploitation of offshore oil resources,the oil spill accidents occur frequently,resulting in serious damage and losses.It is very important to identify the source of oil spill quickly and accurately,which is helpful to carry out the cleaning operation,to solve the problem of responsibility attribution and dispute.At present,the current of identification of oil spill sources tends to the combination of many methods.High accuracy but time consuming,and it can not meet the demand of rapid identification of oil fingerprints.Therefore,this study proposes to combine infrared spectroscopy and gas chromatography to identify oil fingerprints,and to realize the complementary advantages of the two methods,so as to provide a fast,simple and accurate oil spill identification technology.Fourier Transform Attenuated Total Reflection Infrared Spectroscopy is simple to operate and fast to detect.The accuracy of gas chromatography is high.In this paper,The advantagesgas of gas chromatography and Fourier Transform Attenuated Total Reflection Infrared Spectroscopy are combined to detect and analyze the content of n-alkanes and the short term weathering characteristics(weathering time for 40 days)of 0#diesel oil,-35#diesel oil,120#fuel oil,Daqing crude oil and Inner Mongolia crude oil.The correlation analysis of the two methods is carried out,and then the relation is coupled to realize the quick identification of oil fingerprint.The experimental results show that the infrared spectra of diesel and crade oil are similar,characteristic absorption peaks are respectively located at about 2954cm-1,about 2920cm-1,about 2850cm-1,about 1460cm-1,1376cm-1 and about 720cm-1,and all of them are n-alkanes vibration frequency.The infrared spectra graph of 120#fuel oil have eight characteristic absorption peaks,located at 2952cm-1,2920cm-1,2851cm-1,1595cm-1,1455cm-1,1375cm-1,811cm-1 and 749cm-1,and the characteristic absorption peaks are the vibration frequency of n-alkanes and arene.The original characteristic peaks position of the infrared not change after weathering,but there are two new characteristic absorption peaks in the graph of diesel and crude oil,located at about 1700cm-1 and about 1600cm-1.There are significant differences in the graph of gas chromatogram and the distribution of n-alkanes in different kings of oil.After weathering,the total n-alkanes concentration of petroleum products decrease,but the concentration of the medium carbon number n-alkanes increase.The absorption intensity at about 1700cm-1 of diesel oil and crude oil enhance with the deepening of weathering degree.The absorption intensity at about 720cm-1 increase with the increasing of the number of connected CH2.According to these,the relation coupling of gas chromatography and infrared spectroscopy are fitted and a method for rapid identification of oil fingerprints was proposed.Estimation of oil weathering time by infrared spectrum map data,and then obtained the n-alkane component proportion of gas chromatography experiments by coupling relation equation of gas chromatography,infrared spectroscopy and weathering time.Therefore,the relevant informations of gas chromatography experiment were indirectly obtained by infrared spectrum experiment,so as to meet the purpose of quick and accurate identification of oil fingerprint.Verification of this method shows that the relationship coupling is good.However,oils weathering degree is different in different seasons,which leads to the error of weathering time estimation.After the calibration,the precision of the method is improved obviously.