Detection method and sampling device for PM2.5 in exhaled gas

Abstract

The invention relates to a detection method and a sampling device for PM2.5 in exhaled gas and belongs to the technical field of analysis of physical and chemical properties of particles. The detection method includes the steps of: 1) sample collection: collecting exhaled gas from breath, and maintaining the temperature of the exhaled gas to be 35-39 DEG C constantly during the gas collection; 2) sample detection: introducing the gas sample into a mono-particle aerosol mass spectrometer for analysis, firstly, the particles in the gas sample pass through two diameter measuring lasers, at certain distance, to perform particle size detection and obtain particle size, and then the particles, under the effect of ionized laser, acquire energy and are ionized into fragment ions, which then enter a flight time mass analyzer to perform detection to obtain charge-to-mass ratio of the fragment ions; and 3) result analysis: analyzing the particle sizes and the charge-to-mass of the fragment ions to acquire partical size spectrum and component spectrum of PM2.5 in exhaled gas. The method achieves real-time online detection on the partical size spectrum and component spectrum, and overcomes defects in the analysis technologies in the prior art.

Description

technical field [0001] The invention relates to a method for analyzing the physical and chemical properties of particulate matter, in particular to a method for analyzing PM in exhaled air. 2.5 detection methods and sampling equipment. Background technique [0002] At present, my country's Beijing-Tianjin-Hebei, Yangtze River Delta, Pearl River Delta and other economically developed areas have frequent haze weather, and the primary pollutant PM 2.5 (Tiny particles with an aerodynamic equivalent diameter ≤ 2.5 μm) seriously exceed the standard. PMs from different sources 2.5 They have different chemical compositions and therefore different toxic effects as well as different physicochemical properties (such as particle size distribution, hygroscopicity, etc.). [0003] Respiratory behavior is the individual exposure to PM 2.5 The most important way, PM with different particle sizes 2.5 During respiration, it will be deposited in different positions of the respiratory trac...

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Problems solved by technology

The advantage of the above analysis method is that the sample is not pre-treated and PM can be retained 2.5 Original information, but the disadvantage is that there is no chemical composition information

[0008] The main analytical means to detect the chemical composition of EBC include spectroscopy, high performance liquid chromatography mass spectrometry (P.Kubáň and F.Foret, Anal.Chim.Acta, 2013), the advantage of this method is that it can evaluate the PM according to the chemical composition 2.5 Possible harmful effects; disadvantages include: (1) No particle size spectrum, that is, it is impossible to know the different chemical composition of PM 2.5 The deposition location, which affects the PM 2.5 Accurate understanding and analysis of toxicity mechanism; (2) non-PM 2.5 Native information, i.e. the detected composition profile is not PM in its native form in exhaled breath 2.5 , exhaled PM 2.5 The chemical composition of the chemical composition may change during the condensation process, so there is the possibility of inaccurate detection results; (3) the water in the exhaled breath will be enriched during condensation, which will dilute the sample (the water content of EBC is about 99.9%), and reduce the concentration of the sample to be tested. concentration, the requirement for method sensitivity becomes higher

However, exhaled PM based on single particle aerosol mass spectrometry 2.5 Analytical methods have not yet been reported

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