This device samples aerosol particulate matter in the northwestern shoulder of Chacaltaya. It has two interchangeable DIGITEL impactors, which allow to sample particles with aerodynamic diameter lower than 10 or 2.5 µm (i.e., PM10 and PM2.5 fractions) at a flow rate of 30 m3 h-1. Samples are collected on pre-baked quartz fibre filters (Ø 150 mm) on a weekly basis or at higher frequency for high filter loadings.
Filters are transported and stored at -18ºC and then shipped to the LGGE in France, where the soluble fraction is analyzed to determine its content of major and minor ions (in a Dionex Ion Chromatograph), organic and elemental carbon (in a Sunset Lab TOC applying the EUSSAAR_2 protocol) and anhydrous monosaccharides (in a High Performance Liquid Chromatography coupled to a Pulse Amperometric Detector).