Study of ¹³C ratio isotope composition of Lebak Bulus rainwater, South Jakarta

¹³C isotope composition of Lebak Bulus, South Jakarta rainwater samples have been analyzed and interpreted. The aim of study is to know about the impact of emission gas from anthropogenic activities on ¹³C isotope composition of Lebak Bulus, South Jakarta rainwater. Rainwater samples were collected and monitored from PAIR - BATAN, Lebak Bulus - South Jakarta on September 2009 until June 2010. The Method is referred to DIC (Dissolved Inorganic Carbon) of atmospheric Carbon dioxide absorbed by rainwater. The ¹³C isotope ratio (δ¹³C) was measured using mass spectrometer SIRA-9 VG-ISOGAS. After ten months of measurement it showed that δ¹³C value in February 2010 was -10.71 ⁰/₀₀, the most depleted value compared with another nine months, while the high measurement results (enrich) obtained in December 2009 amounted to -8.52 ⁰/₀₀. The results showed that atmospheric CO₂ gas levels in Lebak Bulus, South Jakarta were more depleted compared to the composition of the isotope ratio of δ¹³C atmospheric clean air area of only -8.2 ⁰/₀₀. The decline in the value of Lebak Bulus atmospheric isotope ratio composition, South Jakarta becomes more negative than the clean air atmosphere, indicating that there is addition of CO₂ emissions from anthropogenic activity. (author)