Dithizone, commonly known as the lead reagent, is the most widely used organic color developer in colorimetric analysis. It can be used to determine trace heavy metal ions, such as Pb2+, Hg2+, Zn2+, Cd2+, etc. The molecular formula is C6H5NHNHCSN=NC6H5. Appearance is a purple-black crystalline powder. Insoluble in water and inorganic acids. Soluble in chloroform and carbon tetrachloride, in which the solubility in chloroform is greater, and the solution is green. Slightly soluble in hydrocarbon solvents. An active hydrogen atom in the dithizone molecule is replaced by a metal, and the nitrogen atom forms a coordination bond with the metal ion to form a chelate complex. The solution is orange or red, and the reaction is very sensitive.
Precautions for operation: Airtight operation, local exhaust. Prevent dust from being released into the workshop air. Operators must undergo special training and strictly abide by operating procedures. It is recommended that operators wear self-priming filter dust masks, chemical safety goggles, anti-virus infiltration work clothes, and rubber gloves. Keep away from fire and heat sources, and smoking is strictly prohibited in the workplace. Use explosion-proof ventilation systems and equipment. Avoid generating dust. Avoid contact with oxidants. Equipped with the corresponding variety and quantity of fire fighting equipment and leakage emergency treatment equipment. Empty containers may be harmful residues.
Storage Precautions: Store in a cool, ventilated warehouse. Keep away from fire and heat sources. Protect from direct sunlight. The package is sealed. should be kept away from oxidizer, do not store together. Equipped with the appropriate variety and quantity of fire equipment. Storage areas should be provided with suitable materials to contain spills.