MEASUREMENTS
The group on geochemistry of atmospheric aerosols operates a network of monitoring stations
for long term and intensive measurements (online/offline) of atmospheric aerosols
and gaseous precursors.
The sites integrating the network are equipped with a similar set of instruments.
Type of instruments varies in accordance to the research objectives at each site.
Measurements online
(MSA – Montsec : MSY – Montseny : BCN – Barcelona. Click the instrument name for more info)
Aerosols
Columnar measurements
Gaseous compounds
Meteo
At each station we measure Temperature, Precipitation, Humidity, Wind direction, Wind speed and Trajectories.
In MSA parameters are recorded by a meteorological tower, located at the Montsec observatory and belonging to the Catalan Meteorological Service (METEOCAT).
In MSY parameters are recorded by the IDAEA since 2008
In BCN parameters are recorded by a Faculty of Physics of the University of Barcelona.
Measurements offline
Sampling
PM10, PM2.5 and PM1 samples are collected on quartz filters by sequential High volume samplers MCV (CAV/A MCV, 30 m3 h-1) and DIGITEL (DHA 80, 30 m3 h-1). Both fractions are simultaneously sampled, at a ratio of 1 24 h filter every 3 days. The sampling schedule is similar at the three sites. This sampling strategy accounts for 90 filters sampled per each PM fraction at each site per year. Since 2011 sampling is performed simultaneously at the three sites.
| Starting year | |||||
| PM fraction | Hi VOL sampler | Time | MSA | MSY | BCN |
| PM10 speciation | MCV / DIGITEL DH80 | 24 h | 2005* | 2002*** | 2002 |
| PM2.5 speciation | MCV / DIGITEL DH80 | 24 h | — | 2002 | 2002 |
| PM1 speciation | MCV / DIGITEL DH80 | 24 h | 2010 | 2009 | 2009 |
In addition, at MONTSENY, PM10 and PM2.5 samples are collected on quartz filters by sequential low volume samplers Partisol (2025, 1 m3 h-1), equipped with denuders for artifact-free OC/EC determinations following EUSAAR protocols. Both fractions are simultaneously sampled, at a ratio of 1 24 h filter out of 3 days.
PM10, PM2.5 and PM1 levels are determined gravimetrically by weighing the filters before and after sampling.
Chemical analysis
Levels of major and trace elements are determined for each filter following the methodology devised by the research group. This method summarized in the table below permits to determine the concentrations in ambient air of more than 70 elements.
| Elements | Sample treatment | Analytical technique |
|---|---|---|
| Al, Mg, Ca, Fe, Na, K, S, P | Acidic digestion ½ filter HF:HNO3:HClO4 |
Inductive Coupled Plasma Atomic Emission Spectrometry (ICP AES) |
| 50 elements: Li, P, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Cd, Sn, Sb, Ba, La, Pb, among others |
Acidic digestion ½ filter HF:HNO3:HClO4 |
Inductive Coupled Plasma Mass Spectrometry (ICP MS) |
| NO3–, SO42-, NH4+ and Cl– | Water extraction ¼ filter |
Ion Chromatography HPLC |
| OC, EC,(TC) | SUNSET OCEC analyzer |
