蒸馏-比色法测定新鲜竹笋中二氧化硫

Determination of sulfur dioxide in fresh bamboo shoots by distillation-colorimetric method

目的:建立鲜竹笋中二氧化硫的蒸馏比色测定方法。方法:利用蒸馏法处理样品,采用在密闭容器中对鲜竹笋进行加热蒸馏,以释放鲜竹笋中的二氧化硫,释放物用水吸收,用与甲醛及盐酸副玫瑰苯胺作用生成紫红色络合物,与标准系列比较定量。该方法能有效的排除常规浸泡液自带颜色对实验检测的影响。结果:在最佳测试条件下,该方法的最低检出限为1mg/kg,线性关系良好,线性回归方程为Y=0.06486X+0.02107,相关系数为r=0.9998,方法的精密度在2.72%~4.55%。回收率在94.5%~99.2%之间。结论:该方法操作简单,灵敏度高,结果准确。适用于鲜竹笋及鲜货食品中二氧化硫的测定。

Objective:To establish a colorimetric method for the determination of sulfur dioxide in fresh bamboo shoots.Methods:Fresh bamboo was treated by distillation,and the sulfur dioxide was released during heating distillation in a closed container.Released sulfur dioxidewas absorbed by water and then reacted with formaldehyde and paratylamine hydrochlorideto form a purple-red complex.This method can effectively eliminate the influence of the color in the immersion liquid.Results:Under the best test conditions,the minimum detection limit of this method was 1 mg/kg,the linear relationship was good,the linear regression equation was Y=0.06486 X+0.02107.The correlation coefficient was R=0.9998,the precision of the method was 2.72%~4.55%and the recovery rate was between 94.5%and 99.2%.Conclusion:The method is simple,sensitive and accurate.It is suitable for determination of sulfur dioxide in fresh bamboo shoots and other fresh foods.