Study On The Deteroination Of Phenanthrene And Methylation Product By Using GC-MS/MS

Alkylated polycyclic aromatic hydrocarbon(APAHs)is a kind of persistent organic pollutants,they exist widely in various kind of media environment such as water,soil,and organism.Their toxicity is higher than the toxicity of their parent PAHs and this is a serious threat to people's health.Methylphenanthrene as a typical alkylation product of polycyclic aromatic hydrocarbons in methylation product has gradually attracted scholars'attention.And methyl phenanthrene ratios as one kind of important molecular geochemical indicators and one of the important indexes is to measure the maturity of organic matter in the evaluation of geological,and it has a good linear positive correlation with the most common indexes of vitrinite reflectance.In order to implement the analysis of high-throughput automated,which evaluates and accumulates the resource of oil and gas;strengthen the promotion and application of methylphenanthrene ratio in shale reservoir maturity evaluation.The concentration of phenanthrene and methylphenanthrene obtained by calculating the m/z of 178 and 192in the peak area of chromatogram.Because the tandem mass spectrometry has the advantages of good selectivity,high sensitivity,high accuracy,and automated high throughput,in the paper the tandem mass spectrometry is used for quantitative analysis phenanthrene and methyl phenanthrene in the Ordos basin shale and Hailuogou moss,which is good for excluding the influence from a large number of interfering ions,and reducing the background noise of the mass spectrometry,so as to improve selectivity and sensitivity of the analytical method,to simplify separation and purification steps of complex sample,and to achieve rapidly quantitative phenanthrene and methyl phenanthrene,finally it can use for the detection of APAHs in environmental and the promotiono of rganic maturity medium in shale.In this paper,in order to improve the accuracy of instrument of qualitative and quantitative,the condition of the capillary column,the ion pair,and the optimum collision energy conditions were selected.In order to achieve the high throughput analysis,on the condition of the isomer of methyl phenanthrene have reached the basic separation,compression instrument analysis to optimize the program of heating,to lead the instrument detection time reduce to 22 min.Compared with gas chromatography mass spectrometry(GC-MS)method,the signal-to-noise ratio of phenanthrene and methyl phenanthrene were raised more than 80 times.The instrument conditions of the gas chromatography tandem mass spectrometry(GC-MS/MS):The sample extract(1.0?L)was injected in the splitless mode into Rxi~@-1MS(30 m×0.25 mm×0.25?m);and helium was as the carrier gas at the flow rate of 1.0mL/min;the injector temperature was 300?;the oven temperature program was set as follows:holding for 2 min at 60?,then 30?/min up to 180?,then 4?/min up to 230?,and then to 40?/min to 280?and holding for 2.2 min;EI as ion source and its energy was 70 eV,ion source temperature is 260?;the transfer line temperature is 280?;Tandem mass spectrometry was in multiple reaction monitoring(MRM)mode and the solvent delay time was 9 min.The results showed that the scope of linear correlation of the method was well from 0.1 to 1000 ng/mL,the correlation coefficients were greater than 0.9997,the limit of detection(LOD)was from 0.01 to 0.06 ng/mL,the limit of quantitation(LOQ)was from 0.07 to 0.58 ng/mL.the relative standard deviation of the same day was from 0.02%to 5.88%,the relative standard deviation of different day was from2.25%to 9.75%,in accordance with the methods of reproducibility and precision,the test results shows that the relative standard deviation was less than 10%,which means the precision of the method was good,the analysis the method was reliability and applicability.The extraction effect of soxhlet extraction and ultrasonic assisted extraction were compared to using of the instrumental analysis established method in shale samples,the extraction effect of ultrasonic assisted was better than phenanthrene,and the extraction effect of soxhlet extraction was slightly higher than ultrasonic extraction to methylphenanthrene,The purpose of this experiment is to establish an analysis method of high flux automated and this experiment based on the optimization of ultrasonic assisted extraction conditions:the mixed solvent of dichloromethane/hexane=2:1 was extraction solvent and dosage was 150 mL(three times),the time of extraction was50min;Because of the GC-MS/MS had a strong anti-interference ability,other organic components had a little of affection to phenanthrene and methyl phenanthrene,,so shale samples could be directly detected and need not to go through the group separation In the detection of shale samples,the concentration of phenanthrene was from 165.12 to173.4 ng/g,the concentration of methylphenanthrene was from 213.50 to 981.84 ng/g.The recoveries were from 69.55%to 83.16%,indicated that the method is feasible.In the experiment,compared with Soxhlet extraction and ultrasonic assisted extraction before processing the moss samples,the ultrasound assisted extraction was a better method to phenanthrene and methylphenanthreneo in moss.This experiment based on ultrasonic assisted extraction conditions were optimized:the mixed solvent of hexane/dichloromethane=2:1 as extraction solvent and dosage was 70 mL(two times),the time of extraction was 40min;because there was a lot of moss pigment that extracted in the extraction process,which would seriously damage the instrument without purificating,so the purification conditions were as follows:Eluted by using 10 mL hexane,and then using the mixed solvent of 20 mL hexane/dichloromethane=1:1,was a good elution effect to phenanthrene and methyl phenanthrene.In the detection of moss samples,the concentration of phenanthrene was from 115.71 to 146.34 ng/g,the concentration of methyl phenanthrene were from 75.84 to 136.92 ng/g,the The recoveries of the method was between 68.34%and 81.69%,which indicated that the method was feasible.