离子色谱法测定天麻中二氧化硫残留量

Study on the method for detection of residual sulfur dioxide in Gastrodiae rhizoma

目的建立离子色谱法测定天麻中二氧化硫残留量的检测方法。方法样品经30mL.L-1盐酸水溶液蒸煮,氮气作载气,导出后用30mL.L-1双氧水氧化吸收,再煮沸除去剩余的双氧水,用去离子水转移至25mL量瓶中,并稀释至刻度作为供试溶液,使用离子色谱仪分析。用A-SUPP5-150阴离子分析柱,3.2mmol.L-1碳酸钠溶液-1.0mmol.L-1碳酸氢钠溶液为淋洗液,流速为0.7mL.min-1;进样量为20μL。结果线性范围(以SO2计)为1.667～133.38μg.mL-1,平均回收率为98.0%。结论测定方法简便,精密度、重复性良好,准确度较高。

Objective To establish an ion chromatographic method for the determination of residual sulfur dioxide in Gastrodiae rhizoma.Methods Steam from samples distilled by 30 mL·L^-1 hydrochloric acid solution,transfered by N2,was absorbed by 30 mL·L^-1 hydrogen peroxide.The absorption liquid was analyzed by ion chromatography.A-SUPP5-150 anion analytical column was used with an eluent consisted of 3.2 mmol·L^-1 Na2CO3 and 1.0 mmol·L^-1 NaHCO3 solution.The velocity of flow rate was 0.7 mL·min-1.Results Linear range was 1.667 -133.38 μg·mL^-1（calculated by SO2）,and the average recovery was 98.0%.Conclusion The method is easy to operate and shows good reproducibility and accuracy for the determination of residual sulfur dioxide in Gastrodiae rhizoma.