Assessment of the relationships between iodine isotopes (¹²⁷I, ¹²⁹I) and atmospheric elements in precipitation from Sweden

Abstract

In order to assess the relationships between iodine isotopes (¹²⁷I, ¹²⁹I) and atmospheric elements, the concentrations of chlorine and bromine were determined using high resolution inductively coupled plasma mass spectrometry with an X SeriesII ICPMS (Thermal Electron Corporation) machine for precipitation samples collected during the period 2000–2006 at three different stations (Abisko, Uppsala and Kvidinge) in Sweden. For concentration of chlorine, Abisko in the north has the lowest average concentration, 0.6 mg/L, Kvidinge showing a little higher, 1.13 mg/L, and Uppsala exhibits as the highest concentration, 2.93 mg/L. As to bromine, the median concentration was 3.07, 3.43 and 4.73 μg/L for station Abisko, Uppsala and Kvidinge, respectively. Chlorine and bromine show the highest correlation with ¹²⁷I in Kvidinge (r < 0.7) than those in Uppsala and Abisko. The different correlations of ¹²⁷I–Cl and ¹²⁹I–Cl, or ¹²⁷I–Br and ¹²⁹I–Br are attributed to their respective sources to the atmosphere. Furthermore, the results show that iodine isotopes (¹²⁷I, ¹²⁹I) have high correlations with Cl and Br than the other atmospheric elements.