在线蒸馏-流动注射法测定食糖中的二氧化硫

目的建立在线蒸馏-流动注射法测定食糖中二氧化硫含量的分析方法。方法采用全自动流动注射分析仪测定食糖中的二氧化硫,对硫酸溶液浓度和反应温度进行优化,并与国家标准测定方法进行比较。结果在最佳条件下,方法在0.5~10 mg/L的质量浓度范围内具有良好线性(r=0.9994),方法的检出限为5.0 mg/kg,精密度实验的相对标准偏差(relative standard deviation,RSD)为1.43%~2.01%,平均回收率为93.2%~102.6%。结果证明该方法比国标蒸馏法灵敏度更高。结论该方法具有灵敏度高、重复性好等优点,以自动的在线蒸馏代替了较为繁琐的传统蒸馏方式,检测过程易操作,实现自动化,提高了检测效率,适用于食糖中二氧化硫的测定。

Determination of sulfur dioxide in sugar by online distillation-flow injection analysis

Objective To establish a method for the determination of sulfur dioxide in sugar by online distillation-flow injection analysis. Method The content of sulfur dioxide in sugar was determined by automatic flow injection analyzer. The sulfuric acid concentration and reaction temperature were optimized and compared with the national standard method. Results Under the optimum conditions, the method had a good linearity (r=0.9994) in the concentration range of 0.5-10 mg/L and the limit of detection was 5.0 mg/kg. The precision test relative standard deviation (RSD) was 1.43%-2.01% and the average recovery rate was 93.2%-102.6%. The result showed that the sensitivity of this method was better than the national standard distillation. Conclusion This method has good sensitivity and repeatability. In addition, the online distillation-flow injection analysis takes place of tedious traditional distillation method and the detection process is easy to operate with automation, which can improve the detection efficiency and is suitable for the detection of sulfur dioxide in sugar.