碱性溶液提取-离子色谱法测定中药中二氧化硫残留量

Determination of sulfur dioxide in traditional Chinese medicine by alkaline solution extraction and ion chromatography

目的:建立中药中二氧化硫的测定方法。方法:样品用碱性溶液提取,甲醛作稳定剂,经C18小柱净化。色谱柱为IonPac AS11-HC型离子交换柱,流动相为15 mmol.L-1 KOH,加电自动抑制模式,用配有电导检测器的离子色谱仪测定亚硫酸根。结果:二氧化硫的残留量在1～100μg线性关系良好r,=0.999 2,检测限为0.53 mg.kg-1,平均回收率为103.7%。结论:该法具有检测时间短、偶然误差小、灵敏度高、操作简便等优点,适于大批中药样品的检测。

Objective： An ion chromatographic method was developed to analyze sulfur dioxide in traditional Chinese medicine （TCM）. Method： The samples were extracted with alkaline solution and reacted with formaldehyde to form hydroxymethyl sulfonic acid. The Extracts were cleaned by Cis column and SO32- was determined with ion chromatography equipped with a conductance detector. In the method, AS11-HC chromatographic column was used and the mobile phase was 15 mmol · L-1 KOH. Result： The calibration curve was in good linearity in the range of 1 to 100 μg （r =0. 999 2）. The detection limit was O. 53 mg · kg-1 and the average recovery was 103.7%. Conclusion： The method is simple, sensitive, precise, short-time-consuming, and the random error is smaller, which is applicable to the testing of large quantity batches of TCM.