Μετρήσεις ιοντικής σύστασης λεπτών αιωρούμενων σωματιδίων στην ανατολική μεσόγειο με υψήλη ανάλυση
High resolution ionic composition measurements of fine mode aerosols in the eastern mediterranean
Βαρδαβάς, Αλέξανδρος Ηλ.
A PILS-IC system was set up and modified in Crete to test its capability to measure anion concentrations arising from aerosols. The PILS of the experiment was based at the Environmental Chemical Process Laboratory (ECPL) of the Chemistry Department at the University of Crete. The location of the University of Crete is at Voutes located not more than 20 km from the city of Heraklion, with small populations close by and the main electricity power plant of the area is situated near the sea about 10 km away. However, because of the wind directions we are interested to see how accurately the PILS is able to rapidly sample air parcels from the wider geographical region.
Various anions were detected but their IC analysis was difficult due to low concentrations except for the sulfate. Although the IC was able to measure several anion concentrations ( these included MSA, Cl-, Br-, NO3-, SO4-, HPO4- and oxalate anions ) using a standard solution of high concentration, the PILS sample solution obtained from the air sample resulted in the detection and concentration measurement of only the sulfate anion by the IC.
Because of the importance of the concentration of SO4-2 in the atmosphere and the location were the sampling was done, the main focus was the SO4-2 anions. Sulfate concentrations were monitored approximately every 20 minutes for the period April-June 2011, which included a dust event and a major pollution event arising from the Athens Metropolitan area. Tests were also performed to ascertain the effects of operating the system with and without denuders on the measured sulphate concentrations using different IC eluents that demonstrated the effectiveness of the denuders in obtaining better concentration results.