Determination of sulfite content in food by steam distillation-ion chromatography

Objective To establish an ion chromatography method for the determination of sulfite content in food by steam distillation. Methods The sample was extracted by means of steam distillation and absorbed by 10% triethanolamine solution through a 0. 45 μm membrane and then analyzed by ion chromatography with electrical conductivity detector. The quantification was performed by external standard. The Metrosep A Supp 10 column was selected as the separation column,and 5. 0 mmol / L Na 2 CO 3 + 5. 0 mmol / L NaHCO 3 with 2% acetone was used as mobile phase. The flow rate was set at 0. 8 ml / min and the column temperature was set at 40 ℃,sample volume was 100 μl,the sulfite ion was separated well. Results Under the regulated condition,the standard curves of sulfite content were linear in the concentration range of 0. 0 μg / ml ~ 6. 0 μg / ml with correlation coefficients of 0. 9991. The limit of detection was 2. 0 mg / kg,the recoveries ranged from 90. 2% to 105. 4% and relative standard deviations were from 3. 1% to 6. 8%. Conclusion The method is simple,rapid,accurate and reliable. It can be applied to determine the sulfite content in food.