Aerosol Counterflow Two-Jets Unit for Continuous Measurement of the Soluble Fraction of Atmospheric Aerosols
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- 作者：Pavel Miku
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- 刊名：Analytical Chemistry
- 出版年：2005
- 出版时间：September 1, 2005
- 年：2005
- 卷：77
- 期：17
- 页码：5534 - 5541
- 全文大小：167K
- 年卷期：v.77,no.17(September 1, 2005)
- ISSN：1520-6882
文摘
A new type of aerosol collector employing a liquid atlaboratory temperature for continuous sampling of atmospheric particles is described. The collector operates onthe principle of a Venturi scrubber. Sampled air flows athigh linear velocity through two Venturi nozzles "atomizing" the liquid to form two jets of a polydisperse aerosolof fine droplets situated against each other. Counterflowjets of droplets collide, and within this process, the aerosolparticles are captured into dispersed liquid. Under optimum conditions (air flow rate of 5 L/min and water flowrate of 2 mL/min), aerosol particles down to 0.3 
m indiameter are quantitatively collected in the collector intodeionized water while the collection efficiency of smallerparticles decreases. There is very little loss of fine aerosolwithin the aerosol counterflow two-jets unit (ACTJU).Coupling of the aerosol collector with an annular diffusiondenuder located upstream of the collector ensures anartifact-free sampling of atmospheric aerosols. Operationof the ACTJU in combination with on-line detectiondevices allows in situ automated analysis of water-solubleaerosol species (e.g., NO2-, NO3-) with high time resolution (as high as 1 s). Under the optimum conditions, thelimit of detection for particulate nitrite and nitrate is 28and 77 ng/m3, respectively. The instrument is sufficientlyrugged for its application at routine monitoring of aerosolcomposition in the real time.
m indiameter are quantitatively collected in the collector intodeionized water while the collection efficiency of smallerparticles decreases. There is very little loss of fine aerosolwithin the aerosol counterflow two-jets unit (ACTJU).Coupling of the aerosol collector with an annular diffusiondenuder located upstream of the collector ensures anartifact-free sampling of atmospheric aerosols. Operationof the ACTJU in combination with on-line detectiondevices allows in situ automated analysis of water-solubleaerosol species (e.g., NO2-, NO3-) with high time resolution (as high as 1 s). Under the optimum conditions, thelimit of detection for particulate nitrite and nitrate is 28and 77 ng/m3, respectively. The instrument is sufficientlyrugged for its application at routine monitoring of aerosolcomposition in the real time.