本试剂盒基于褪色反应测定柠檬酸（CA）含量。Fe(III)-磺基水杨酸络合物呈紫红色，CA 可使其褪色至橙红，于 470 nm 处测定吸光度下降值，该下降幅度与 CA 浓度在一定范围内呈正比，以此定量样品中的 CA 含量。CA 广泛存在于食品、医药及工业领域，亦是三羧酸循环的关键代谢物。
This kit determines the content of citric acid (CA) based on a fading reaction. The Fe(III)-sulfosalicylic acid complex exhibits a purple-red color, which can be faded to orange-red by CA. The decrease in absorbance is measured at 470 nm, and the extent of this decrease is proportional to the CA concentration within a certain range, thereby enabling the quantification of CA in the sample. CA is widely present in food, pharmaceutical, and industrial fields, and is also a key metabolite in the tricarboxylic acid (TCA) cycle.
危险品化学品经营许可证（带存储）