This kit employs an enzyme‑coupled method for the determination of citric acid content. Citrate lyase cleaves citric acid to oxaloacetate, which is then reduced by NADH to malate in a reaction catalyzed by malate dehydrogenase, with concomitant oxidation of NADH to NAD⁺. The decrease in NADH absorbance is monitored at 340 nm, and this decrease is directly proportional to the citric acid content in the sample, thereby enabling quantitative detection.
危险品化学品经营许可证（带存储）