Analytical performance of single particle aerosol mass spectrometer for accurate sizing and isotopic analysis of individual particles
Analytical performance of single particle aerosol mass spectrometer for accurate sizing and isotopic analysis of individual particles
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DOI：
10.1016/j.atmosenv.2023.119759
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发表时间：
2023-04
影响因子：
5
通讯作者：
Yongyang Su;Guanyi Wei;Wei Wang;Ruiyang Xi;Xi Wang;Jiang Xu;Zhimin Li
中科院分区：
文献类型：
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作者：
Yongyang Su;Guanyi Wei;Wei Wang;Ruiyang Xi;Xi Wang;Jiang Xu;Zhimin Li
商用和新单粒子气溶胶质谱仪(SPAMS)已广泛应用于环境气溶胶监测和源解析。然而，粒度测量容易受到环境压力波动和取样口堵塞的影响。定量分析能力较差，同位素测量报道较少。本文的目的是评估垃圾邮件的分析性能，扩大其应用范围。首先，测量了不同密度和大小的标准粒子在不同条件(气动透镜、上游压力和载气)下的飞行时间。提出了一种考虑透镜几何形状(加速喷嘴直径)、颗粒参数(密度、直径和形状因子)以及运行条件(透镜上游压力和载气)影响的颗粒尺寸校准、测量和校正的通用方法。然后，当引入含有单一元素的液滴时进行同位素测量。在质谱图中观察到金属氧化物和金属团簇离子，表明样品液滴的电离不完全。为了修正测得的同位素比值，仔细评估了质量判别效应。结果表明，所研究元素的校正同位素比值的可达精度为5%。对于电离势或键能较大的元素，仪器性能相对较差。最后，对Ag/Eu2O_3悬浮液和黄饼/乙醇悬浮液进行了粒度、元素和同位素分析。我们证实了悬浮液引入过程中的质量歧视效应可以用溶液引入过程中得到的质量歧视修正因子来修正。这些悬浮颗粒物中的Ag、Eu和U均处于自然丰度。黄饼中的铀被鉴定为杜兰酸钠(Na2U2O7)，体积当量直径约为65 nm。本文的工作对仪器的改进和推广应用具有一定的参考价值。
The commercial Hexin Single particle aerosol mass spectrometer (SPAMS) has been widely used for environmental aerosol monitoring and source apportionment. However, particle size measurement is easily affected by environment pressure fluctuation and sampling orifice clogging. The capability for quantitative analysis is poor, and few isotope measurement has been reported. This paper aims to evaluate the analytical performance of SPAMS and extend its application. First, the flight time of standard particles having different densities and sizes was measured under various conditions (aerodynamic lens upstream pressure and carrier gas). We proposed a universal method for particle size calibration, measurement and correction, taking into account the effects of lens geometry (acceleration nozzle diameter), particle parameters (density, diameter, and shape factor), and operating conditions (lens upstream pressure and carrier gas). Then, isotope measurement was performed when introducing a solution droplet containing a single element. Metal oxide and metal cluster ions were observed in the mass spectrum, indicating incomplete ionization of the sample droplet. The mass discrimination effect was carefully evaluated to correct the measured isotope ratio. Results show that the achievable accuracy of the corrected isotope ratio for elements investigated was 5%. The instrumental performance was relatively poor for elements having great ionization potential or bond energy. Finally, Ag/Eu2O3suspension and yellow cake/ethanol suspension were analyzed for size, elemental and isotopic analysis. We confirmed that the mass discrimination effect during suspension introduction could be corrected using the mass discrimination correction factor obtained during solution introduction. The Ag, Eu and U in these suspension particles were all found to be at natural abundance. The uranium in the yellow cake was identified as sodium duranyate (Na2U2O7) with volumetric equivalent diameter of approximately 65 nm. The work presented here is beneficial for instrument improvement and wide application.