After digestion treatment of the soil sample, mercury exists in the form of Hg²⁺ ions. Hg²⁺ can react with dithizone to form an orange complex. After this product is dissolved in chloroform, it exhibits a characteristic absorption peak at 490 nm. By measuring the change in absorbance at this wavelength, the mercury content in the soil can be quantitatively determined.
危险品化学品经营许可证（带存储）