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    气相色谱-质谱法测定汽油中4种金属抗爆剂的含量

    Determination of 4 Metal Antiknock Agents in Gasoline by Gas Chromatography-Mass Spectrometry

    • 摘要: 提出了气相色谱-质谱法测定汽油中四乙基铅、二茂铁、环戊二烯三羰基锰、甲基环戊二烯三羰基锰等4种金属抗爆剂含量的方法。汽油样品中加入一定量的己二酸二乙酯(内标)溶液,使其质量浓度为2.00 mg·L-1,待仪器稳定后,吸取1 μL进行测定。4种目标物在HP-PONA色谱柱上以程序升温条件分离,质谱仪检测。根据保留时间和质谱图定性,特征定量离子结合内标法定量。结果显示:4种金属抗爆剂工作曲线的线性范围为0.10~50.00 mg·L-1,检出限为(3S/N)为0.018 6~0.030 1 mg·L-1;选择8家实验室,对7个加标浓度水平的样品进行精密度试验,结果表明无界外样品和界外实验室,并给出了方法的重复性限和再现性限;选择6家实验室,对空白样品进行3个浓度水平的加标回收试验,4种金属抗爆剂的回收率为95.1%~108%,回收率的相对标准偏差(n=6)为1.2%~3.8%;按照试验方法和原子吸收光谱法(GB/T 8020-2015、SH/T 0712-2002、SH/T 0711-2019)对6个空白加标汽油样品中的铅、锰、铁进行测定,试验方法所得回收率更接近100%。

       

      Abstract: A method for the determination of 4 metal antiknock agents, including tetraethyl lead, ferrocene, cyclopentadiene manganese tricarbonyl and methylcyclopentadiene manganese tricarbonyl in gasoline by gas chromatography-mass spectrometry was proposed. A certain amount of diethyl adipate (internal standard) solution was added into the gasoline sample to make its mass concentration to 2.00 mg·L-1. After the instrument was stable, 1 μL was absorbed for determination. The 4 target compounds were separated on HP-PONA column under the temperature-programmed conditions and detected by the mass spectrometer. The retention time and mass spectra were used for qualitative analysis, and the characteristic quantitative ions combined with internal standard method were used for quantitative analysis. It was shown that the linear ranges of the working curves for 4 metal antiknock agents were 0.10-50.00 mg·L-1, with detection limits (3S/N) in the range of 0.018 6-0.030 1 mg·L-1. The 8 laboratories were selected, and test for precision was made on the samples at 7 spiked concentration levels. The results showed that there were no out-of-bound samples and laboratories, and the repeatability limits and reproducibility limits were given. Test for recovery was made on the blank samples at 3 concentration levels by addition standard method, giving results of 4 metal antiknock agents in the range of 95.1%-108%, and RSDs (n=6) of the recovery values were in the range of 1.2%-3.8%. This method and atomic absorption spectrometry (GB/T 8020-2015, SH/T 0712-2002 and SH/T 0711-2019) were used for the determination of lead, manganese and iron in 6 blank spiked gasoline samples, and the recovery values of this method were closer to 100%.

       

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