离子色谱法测定中药类保健食品中二氧化硫残留量

目的建立保健食品中二氧化硫残留量的检测方法。方法采用加酸蒸馏的方法将供试品中的亚硫酸盐转化为二氧化硫,用双氧水吸收并氧化为硫酸根,采用离子色谱法检测供试品溶液中的硫酸根。以20mmol·L-1 KOH溶液为淋洗液,经Ion Pac AS-11-HC(250mm×4mm)柱分离,电导检测器检测。结果 SO2-4质量浓度在0.1²00μg·mL-1范围内线性关系良好,在饮液和固体制剂中的平均回收率分别为95.6%和92.9%,RSD分别为6.0%和6.6%。结论该方法操作简便,灵敏度高,专属性强,准确度和重复性良好。

Determination of sulfur dioxide in herbal health functional foods by ion chromatography

Objective To establish an ion chromatography method for the determination of sulfur dioxide in herbal health functional foods .Methods The sulfite in samples were transformed into sulfur dioxide by stream distillation with acid and absorbed with hy-drogen peroxide solution .Sulfur dioxide were oxidated to sulfate and detected by ion chromatography .The test solution was sepa-rated by an Ion Pac AS-11-HC （250 mm × 4 mm） column using 20 mmol · L -1 KOH as the eluent and detected by conductivity detector .Results The linear range of SO2 -4 was 0 .1-200 μg · mL -1 .The average recoveries were 95 .6% （RSD 6 .0% ） and 92 .9% （RSD 6 .6% ） for liquid preparations and solid preparations ,respectively .Conclusion The method is simple ,sensitive and selective ,and has good accuracy and reproducibility .