The Particle-Into-Liquid Sampler (Pils) from Metrohm UK is said to be an effective way of producing real-time measurements for assessing air quality. The Pils system can measure particulate pollutants several times an hour and when used in combination with a Metrohm ion chromatography system, inorganic ions such as ammonium, nitrate, sulphate and chloride can be detected and quantified with a cycle time between five and 20 minutes depending upon application.The Pils system uses small quantities of steam to form water droplets on individual aerosol particles. The water droplets containing the dissolved aerosols can then be captured and analysed by ion chromatography. The instrument can be operated unattended for up to 20 days depending upon the volume of reagents and size of denuder and can take samples every five minutes. The current method used for analysing airborne particulates is filter sampling.
The filters collect the aerosol particles usually over a 24-hour period and the results are reported as daily averages. High time resolution means more information can be gathered and trends and cycles can be observed. Applications where the Pils system can be used include indoor air quality monitoring, ambient air quality monitoring, tunnel monitoring, waste transfer and landfill site monitoring, stack emissions monitoring, and emission protection for employees.
Metrohm UK offers a direct online on-site analysis using well-established techniques and no manual sample preparation is needed. In combination with an ion chromatograph it is possible to determine the following species: cations (Na+, NH4+, K+, Ca++, Mg++), anions (Cl-, NO3-, NO2-, SO4--), organic acids (acetate, formate, oxalate), LOD (depending on ion) from 5-100 ng/m3. Full installation and training by a Metrohm applications chemist is included in the price of the system.
