Method for selective determination of polybrominated diphenylethers (BDE-47 and BDE-99) in landfill leachates by capillary gas chromatography and electron-capture detection

摘要

The last few decades have seen dramatic growth in the scale of production and the use of polybrominated diphenylethers (PBDEs) as flame retardants. Consequently, PBDEs such as BDE-47, BDE-99, BDE-153 and BDE-209 have been detected in various environmental matrices. These compounds have also been linked with the disruption of the endocrine systems of man and wildlife. The present research work is aimed at determining the concentration of (PBDEs) in landfill leachates in Tshwane Municipality. A simulated landfill leachate was used to optimise various chromatograph parameters such as oven temperature programme, injector and detector temperature, carrier gas flow rate, and the limit of detection. A Varian GC coupled with ECD detector was used for the analysis. An effective method of recovery was developed using petroleum ether instead of hexane/acetone as reported by the literature. Recoveries of BDE-47 -99 and 209, each at a fortification level of 5ng and 6ng respectively, were in the range of 97.5% to 123% and relative standard deviation of 6 to 12 (n=3). The method developed was applied to leachate samples collected from two landfill sites producing leachates (Temba and Soshanguve) in the Municipality. Results obtained are 0.90 and 0.13mg/l for BDE-47 and 0.48 and 0.21 mg/l for BDE-99 respectively. BDE-209 was not detected. Compared to other studies these concentrations are significantly higher than those reported for Japanese landfill sites. Therefore, there is cause for concern if these leachates were to infiltrate into groundwater.