IC Determination of Chlorine and Bromine in Crude Oil with Sample Treatment by Combustion with Oxygen Bomb

The sample of crude oil was combusted in oxygen bomb and the chlorine and bromine were absorbed in Na2CO3-NaHCO3 solution. The contents of chlorine and bromine in the solution were determined by IC. The Dionex IonPac AS23 column was used as ion exchange column, and a mixture of 4.8 mmol·L-1 Na2CO3 and 1.0 mmol·L-1 NaHCO3 was used as eluent. Linear relationships between values of peak area and mass concentration of chlorine and bromine were obtained in the same range of 0.01-1 mg·L-1, and values of detection limit (3S/N) found were 0.3 mg·kg-1 for chlorine and 0.7 mg·kg-1 for bromine. The proposed method was applied to the analysis of sample of crude oil, giving values of RSD′s (n=6) and recovery in the ranges of 3.5%-4.2% and 91.8%-109% respectively.