IC Determination of Sulfur in Tobacco with Sample Treatment by Oxygen Bomb Combustion

The sample of tobacco was combusted in oxygen bomb, and the SO2 evolved were absorbed and transformed to SO42- in 20 mL aqueous solution containing 0.25 mL of 30% hydrogen peroxide, and the excess hydrogen peroxide was removed by heating to boil for 10 min. The content of sulfur (as SO42-) in the absorption solution was determined by IC. Ionpac AS14 column was used as ion exchange column, and a mixture of 1.8 mmol·L-1Na2CO3 and 1.7 mmol·L-1 NaHCO3 was used as eluent. Linear relationship between values of peak area and mass concentration of sulfur was obtained in the range of 0.02-60 mg·L-1, with detection limit (3s) of the method of 3.24 μg·L-1. The proposed method was used in the analysis of standard sample of tea (GSB-7), the results obtained were in conformity with its certified values. Values of recovery found were in the range of 99.2%-99.7% with RSD′s (n=6) less tnan 1%.