Study On Determination Methods Of Aniline,Nitrobenzene Compounds And Sulfide Content In Industrial Products

The compounds of aniline and nitrobenzene are commonly used as chemical materials,and are widely used in petrochemical,coal,printing and dyeing,medical treatment,construction and other industries.Sulfide is often used as a limit control index in petroleum,diesel and other major industrial products in the world.The quality of industrial products has a great impact on China's economic development,ecological balance and human health.And it has become an important means to evaluate the quality of industrial products by detecting the content of some specific substances in industrial products.Fertilizer and petroleum are two important industrial products of our country,aniline and nitrobenzene compounds are often added to fertilizers as a fertilizer trait modifier or functional additive and too much sulfide in petroleum will do harm to its processing and use.Through the detection of aniline and nitrobenzene compounds in fertilizers and sulfur content in petroleum,it is beneficial to make strong supervision on the quality of fertilizers and petroleum in China.Besides,it can improve the awareness of environmental protection of enterprises,and protect human health.At present,in China,there are few detection methods for aniline and nitrobenzene in fertilizers,and no relevant detection standards have been established.What's more,the partial detection methods of sulfide content in fuel oil are also relatively backward.This paper focuses on the detection methods of aniline and nitrobenzene compounds in chemical fertilizers and the rapid determination methods of sulfide and water content in crude oil and diesel oil.The main research contents are as follows:Determination of aniline and nitrobenzene compounds in fertilizers by gas chromatography-mass spectrometry.In this paper,an analytical method for the determination of aniline and nitrobenzene compounds in fertilizer was developed based on gas chromatography-mass spectrometry?GC-MS?combined with ultrasonic extraction technique,which was optimized on the base of ultrasonic extraction process and experimental conditions of GC-MS.Under optimized experimental conditions,this study carried out adding standard recovery experiments on ammonium chloride fertilizer,potassium chloride fertilizer,potassium dihydrogen phosphate fertilizer,ammonium sulfate fertilizer,urea and potassium dihydrogen phosphate fertilizer and three kinds of imported compound fertilizers.The result shows that the method is suitable for the detection of aniline and nitrobenzene compounds in various fertilizers except potassium dihydrogen phosphate fertilizer.The recovery rate of nitrobenzene compounds in fertilizer samples were 81.3%-109.3%,and the recovery rate of aniline homologues were acceptable values ranged from 55.3%to 85.1%.The detection limit of the method was 1.00-3.00?g/kg and the standard deviation?n=6?is 1.5-9.6%.The recovery rate of aniline homologues was obviously improved by ultrasonic extraction technique,which was attributed to the optimization of ultrasonic extractant,ultrasonic time and extractant dosage.Therefore,the method could be successfully used for simultaneous and accurate determination of aniline and nitrobenzene compounds in fertilizers.Rapid determination of water and sulfide content in crude oil and diesel by near infrared spectroscopy.This study established the prediction model of water and sulfide content in crude oil and sulfide content in diesel oil by near-infrared spectroscopy technique,and discussed the effects of spectral scanning times,spectral range,spectral preprocessing method and modeling method on modeling effects.The crude oil moisture spectrum was pretreated by Savitzky-Golay filter.The 6principal components were modeled optimally in the 6200-8200 cm^-1 spectral region.The second derivative?SD?+Norris Derivative filter was used for the crude oil sulfur spectral pretreatment.The number of principal components is 6,and the modeling effect is best in the 4400-4700 cm^-11 spectral region.The diesel sulfur content spectrum is preprocessed by the second derivative?SD?+Norris Derivative filter,the principal component number is 5,and the modeling spectral region is 4000-6000 cm^-1.A near infrared prediction model for the content of water and sulfide in crude oil and the content of sulfide in diesel oil was established by partial least squares?PLS?method.The correlation coefficients R² of the three models are 0.9899,09963 and 0.9990,respectively.The root mean square error of correction?RMSEC?are 0.0842,0.0696 and 0.0335,respectively.And the correlation coefficients R² of the cross validation set are 0.9853,0.9955 and 0.9987,respectively.The root mean squared error of prediction?RMSEP?are 0.1020,0.0801 and 0.0400,and the correlation coefficients R² are all above 0.98,which can realize the rapid quantitative detection of sulfur in crude oil and sulfide and diesel.