碱性品红法直接测定食品中吊白块含量

Basic Fuchsine Method for the Direct Determination of Sodium Formaldehyde Sulfoxylate in Foods

基于吊白块溶液或含吊白块的样品蒸馏液遇氢氧化钠,游离出二氧化硫和甲醛,与碱性品红反应生成一种紫红色物质,在560 nm处有最大吸收,在一定浓度范围内吸光度与吊白块的含量成一定线性关系。在选定的条件下,该方法的线性范围为0.018～0.70 mg。其响应值与吊白块含量呈强相关性,线性回归方程为Y=0.8862X+0.0165,r=0.9991,回收率97.5%～102.0%,检出限0.005 g/L,RSD=4.4%。结果满意。

Based on the sodium formaldehyde sulfoxylate solution or contain sodium formaldehyde sulfoxylate sample distillation fluid in sodium hydroxide, the free SO2 and formaldehyde, and fuchsine reaction to generate a purple material, and in the 560 nm place had the largest absorption. A certain concentration range absorbance and the content of sodium formaldehyde sulfoxylate had a certain linear relationship. The selected conditions, the method of linear range was 0. 018 - 0. 7 mg, its response value and the content of sodium formaldehyde sulfoxylate was strong correlation, linear regression equation for Y =0. 8862 X ＋0. 0165, r =0. 9991 and the recoveries of 97. 5% -102. 0%, the detection limit of 0. 005 g/L, RSD of 4. 4%, with satisfactory results.