四氯汞钠吸收比色法测定香菇中二氧化硫残留量

Determination of sulfur dioxide residue in Lentinus edodes by sodium mercury tetrachloride absorption colorimetry

目的建立四氯汞钠吸收比色法测定香菇中二氧化硫残留量。方法样品与盐酸蒸馏后反应生成二氧化硫气体,与四氯汞钠溶液混合反应后过滤,取滤液与甲醛及盐酸副玫瑰苯胺作用生成紫红色络合物,与标准系列比色定量,计算得到样品中二氧化硫含量。结果在0~0.16μg/mL浓度范围内,二氧化硫的浓度与吸光度有良好的线性关系, r^2=0.9991。相对标准偏差为1.0%~2.8%,相对极差为3.1%-7.6%。与国标法相比,不存在显著性差异(F<F表)。结论该方法精密度高,准确度好,操作简便,适用于香菇二氧化硫残留量的检测。

Objective To establish a sodium tetrachloromeric absorption colorimetry for the determination of sulfur dioxide residue in Lentinus edodes.Methods The sample was distilled with hydrochloric acid to generate sulfur dioxide gas,which was mixed with sodium tetrachloromeric solution and then filtered.The filtrate was mixed with formaldehyde and pararosaniline hydrochloride to form a purplish red complex,and compared with standard series colorimetric quantity to calculate the sulfur dioxide content in the sample.Results In the concentration range of 0-0.16μg/mL,the concentration of sulfur dioxide had a good linear relationship with the absorbance,r^2=0.9991.The relative standard deviations were 1.0%-2.8%,and the relative ranges were 3.1%-7.6%.Compared with the national standard method,there was no significant difference(F<F table).Conclusion The method has high precision,good accuracy and simple operation,which is suitable for detecting residual sulfur dioxide in Lentinus edodes.