1·Methods The content of formaldehyde in rongalite was determined by sulfurous acid, magenta and acetylacetone spectrophotometry respectively.
方法采用品红亚硫酸法和乙酰丙酮法测定吊白块中甲醛含量，并计算样品中吊白块的含量。
2·The content of dialdehyde starch was determined by spectrophotometry with the color agent alkaline fuchsin - sulfurous acid.
以碱性品红-亚硫酸为显色剂，用分光光度法对双醛淀粉含量的测定条件、灵敏度、回收率进行研究。