| Automotive gasoline and diesel, as one of the important petroleum products, plays an important role in the social economy. For the modern production activities, automotive gasoline and diesel are important means of production, honoured as the lifeblood of modern logistics in traffic transport industry which is related to the smooth progress of industrialization, rubanization, improvement of atmospheric environmental quality and sustainable development of economy and society.However, product quality problems still exist in the development of automotive gasoline and diesel industry. In this paper, anilines, oxygenates, water-soluble inorganic anions and sulfides are used as research objects to establish the new methods for detecting harmful additives in automotive gasoline and diesel, and five main research contents are included in this paper shown as follows. 1. GC-MS was used for the simultaneous determination of six aniline additives(N,N-dimethylaniline, N-methylaniline, aniline, 2-methylaniline, 4-methylaniline and m-toluidine) in gasoline. The sample was separated on a strong polar capillary column of ionic liquid. EI-SIM mode was adopted in MS. Acetophenone was used as the internal standard for quantitative analysis. The linear relationships found between the peak area and the mass ratios of the 6 aniline additives were good in the range of 1-10000 mg/kg, with the detection limits in the range of 0.2-0.3 mg/kg. The recovery rates measured by standard addition method were in the range of 99.6%-120.8%, and RSD was less than 2%. 2. GC-MS was used for the simultaneous determination of methyl tert-butyl ether, tert-butyl ethyl ether, methylal, dimethyl carbonate and 1-methylpropyl acetate in gasoline. 4-methyl-2-pentanone was used as internal standard for qualitative and quantitative detection. The linear relationships found between the peak area and the mass ratios of the two ethers, two esters and one aldehyde were good in the range of 10-10000 mg/kg, with the correlation coefficient more than 0.9994. The detection limits were in the range of 0.6-2.6 mg/kg, and the limits of quantitation were in the range of 1.8-7.8 mg/kg, The recovery rates measured by standard addition method were in the range of 82.0%-114.7%, with RSD in the range of 0.7%-5.0%. It was sensitive, reliable and simple, and was suitable for the simultaneous detection of ethers, esters and aldehydes in gasoline. 3. A new dual-column qualitative and quantitative analysis method involving the combination of strong polar TCEP column and nonpolar DB1 column was established to determine the contents of ether, ester and aldehyde additives in motor gasoline by two-dimensional gas chromatography with a heart-cutting system. The retention time of methyl tert-butyl ether(MTBE), tert-butyl methyl ether(ETBE), methylal, dimethyl carbonate and 1-methylpropyl acetate were confirmed under the column switching and non-switching condition. The linear relationships of five target compounds were good in the range of 10-10000 mg/kg and all the correlation coefficient were in the range of 0.9996-1.0000. The average recoveries of the additives were in the range of 88.4%-114.8%, and the relative standard deviation was between 0.04%-3.7%. The study was shown that the limits of detection of five compounds were 0.38-2.14 mg/kg, and the limits of quantitation were in the range of 1.14-6.42 mg/kg. It is certified that this method exhibited the advantage of easy-handle, high sensitivity, reliable and good reproducibility. It is an ideal analysis method to determine ethers, esters and aldehydes in gasoline. 4. A method of ion chromatography(IC) with suppressed conductivity detection for the simultaneous determination of F-, Cl-, Br-, NO3-, SO42- anions in motor gasoline and diesel oil was established. After ultrasonic extraction with 90%(V/V) methanol aqueous solution and centrifugal separation, the sample in aqueous phase was purified with 0.22 μm hybrid filter membrane, and then quantitatively analyzed by the external standard method using IC instrument with KOH as the eluent. The effects of concentration and flow rate of the eluent, and concentration of methanol aqueous solution on the detection of five anions were investigated. The linear relationships of five anions were good in the range of 0.50-20.00 mg/L and all the linear correlation coefficients were between 0.9990 and 0.9999. The limits of detection of five anions were in the range of 0.01-0.04 mg/kg, and the limits of quantitation were in the range of 0.03-0.13 mg/kg. The average recoveries of target anions in gasoline were in the range of 87.6%-109.7% with relative standard deviations of 0.4%-3.5%. The average recoveries of target anions in diesel oil were 86.8%-110.0% with RSDs of 0.1%-2.9%. This method avoided the high requirements on the instrument, complicated and time-consuming pretreatment process. It was simple, reliable, sensitive and suitable for the simultaneously detecting trace inorganic anions in motor gasoline and diesel oil.5. The method of measuring nineteen sulfides contained in motor gasoline by gas chromatography-sulfur chemiluminescence detector(GC-SCD) was established. The limits of detection of target substances in motor gasoline were 0.03-0.36 mg/kg. The linearity range was between 0.50 and 150.00 mg/L with the correlation coefficients were 0.9762-0.9999. The average recoveries of nineteen compounds in motor gasoline sample were 76.4%-120.0%, with the relative standard deviations(RSD) between 0.5% and 5.7%. It was well separated, sensitive and simple and able to determine the nineteen sulfides content accurately which was very important for the determination of sulfides content and the research on the types and distribution regularities of sulfides in gasoline. |
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