【摘要】 建立了用变色酸光度法测定甲醛的方法。采用浓磷酸和过氧化氢混合体系取代原有方法中使用的具有危险性和腐蚀性的浓硫酸。在浓磷酸介质中,甲醛与变色酸反应生成紫红色化合物,于570 nm波长处作光度测定。在甲醛的质量浓度为0.8-4.8 mg.L-1范围内遵守比耳定律。线性相关系数为0.9933。应用于测定香菇中的甲醛,回收率为92.7%-105.3%。更多还原

【Abstract】 A modification of replacing the hazardous and corrosive conc.sulfuric acid medium in the photometric determination of formaldehyde with chromotropic acid by a medium of a mixture containning conc.phosphoric acid and hydrogen peroxide was proposed.In this conc.phosphoric acid medium,a violet-red compound was formed between chromotropic acid and formaldehyde which is photometrically determined at 570 nm.Beer′s Law is obeyed in the concentration range of 0.8-4.8 mg of formaldehyde per liter,with a correlation coefficient of 0.993 3.Recoveries obtained were in the range of 92.7%-105.3%.更多还原