Wang Weigang, Chen Yan, Li Lei, Zhou Li, Du Xubing, Liu Mingyuan, Ge Maofa
State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China.
J Environ Sci (China). 2022 Apr;114:434-443. doi: 10.1016/j.jes.2021.09.036. Epub 2022 Feb 22.
New particle formation (NPF) is the primary source of nanoparticles and contributes a large number of concentrations of cloud condensation nuclei. In recent years, field campaigns and laboratory experiments have been conducted to promote cognition of the mechanism for NPF and its following growth processes. The chemical composition measurement of nanoparticles could help deepen understanding of the initial step of particulate matter formation. In this work, we developed a nanoparticle chemical ionization mass spectrometer to measure nanoparticles' chemical compositions during their initial growth stage. Meanwhile, a non-radioactive ion source was designed for aerosol charging and chemical ionization. Time of flight mass spectrometer coupled with integrated aerosol size selection and collection module would guarantee the picogram level detection limit and high-resolution ability to measure the matrix of ambient samples. The performance of this equipment was overall evaluated, including the transmission efficiency and collection efficiency of custom-built nano differential mobility analyzer, chemical ionization efficiency, and mass resolution of the mass spectrometer. The high sensitivity measurement of ammonium sulfate and methylammonium sulfate aerosols with diameters ranging from 10 to 25 nm could guarantee the application of this instrument in the ambient measurement.
新粒子形成（NPF）是纳米颗粒的主要来源，并贡献了大量的云凝结核浓度。近年来，已经开展了野外考察和实验室实验，以增进对NPF及其后续生长过程机制的认识。纳米颗粒的化学成分测量有助于加深对颗粒物形成初始步骤的理解。在这项工作中，我们开发了一种纳米颗粒化学电离质谱仪，用于测量纳米颗粒初始生长阶段的化学成分。同时，设计了一种非放射性离子源用于气溶胶充电和化学电离。飞行时间质谱仪与集成的气溶胶尺寸选择和收集模块相结合，将确保皮克级的检测限和高分辨率能力，以测量环境样品的基质。对该设备的性能进行了全面评估，包括定制的纳米差分迁移率分析仪的传输效率和收集效率、化学电离效率以及质谱仪的质量分辨率。对直径范围为10至25nm的硫酸铵和硫酸甲铵气溶胶的高灵敏度测量可以保证该仪器在环境测量中的应用。
