Methods Of The Collection Of Aerosols

Methods Of The Collection Of Aerosols

Methods of the collection of aerosols for analysis

Analysis of the composition of aerosols is very important for the development of many different industries and areas of study; however this analysis is challenging because aerosol particles can be difficult to collect.1 Aerosol particles can be collected onto a substrate and then analysed. The collection surface can be a porous medium such as a filter operating at a low flow rate whereby some or all of the particles suspended in the aerosol flow are retained. In many applications particles from the gas flow are extracted by an externally applied force e.g. in a centrifuge or electrostatic precipitator. The collection process should result in the sample taken being representative of the aerosol in its original state therefore it should not be chemically changed in the process. Characteristics such as mass, number concentration and size distribution of particles should remain unchanged however it is difficult to prevent these changes.2

Aerosols consist of solid or liquid particles in a gaseous medium; therefore the particles must be filtered and/or extracted into solution to prepare for chemical analysis. However carboxylic acid and carbonyl containing compounds present in aerosols react with commonly used organic solvents such as methanol over a timeframe of minutes to hours. Although an extraction solvent can be selected so that it does not react with the aerosol particles, the solvent used will be dependent on the

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