In the process of synthesizing illegal drugs, law enforcement agencies usually focus on monitoring and identifying the following types of raw materials (precursor chemicals) to prevent illegal manufacturing and trafficking of drugs. These precursor chemicals are often used to synthesize illegal drugs such as methamphetamine (ice), heroin, and cocaine. 1. **Ephedrine and Pseudoephedrine** These compounds are key precursors for the illegal synthesis of methamphetamine and are commonly found in over-the-counter cold medicines. Due to their importance in drug manufacturing, many countries impose strict restrictions on their purchase and sale. 2. **Acetic Anhydride** Acetic anhydride is mainly used in the synthesis of heroin and is a strictly regulated chemical. Law enforcement agencies usually monitor its import, export, and large-scale procurement activities. 3. **Phenylacetic Acid** As a precursor for the synthesis of cocaine and other chemical drugs, the circulation and distribution of phenylacetone is closely monitored. 4. **Acetone** Although acetone is widely used in industry and households, unusually large purchases may attract law enforcement attention due to its use in the synthesis of certain drugs. 5. **Nitric Acid and Hydrochloric Acid** These strong acids are used as catalysts or reactants in the synthesis of certain drugs, and their purchase and storage are also regulated. 6. **Ammonia** Liquid ammonia plays an important role in the synthesis of many illegal drugs, especially as an intermediate step in certain synthesis processes. 7. **Methyl Iodide and Other Organic Bromides** These organic halides are used in certain highly effective drug synthesis methods, and law enforcement agencies monitor their circulation. 8. **Sulfuric Acid** As a common industrial reagent, sulfuric acid is also used in the production of certain drugs, especially in the production of methamphetamine. **Enforcement measures include, but are not limited to:** - **Sales monitoring**: Limiting and recording the purchase quantity and frequency of these chemicals, especially sales to individuals and small businesses. - **Import and export controls**: Strictly monitoring the cross-border transportation of these chemicals to prevent illegal import or export. - **Supply Chain Tracking**: Trace the supply chain of these chemicals to identify and combat illegal production networks. - **Public Education**: Raise awareness among the public and businesses to promptly report suspicious purchases and sales. Through strict regulation of these key precursor chemicals, law enforcement agencies can effectively reduce the production and circulation of illegal drugs and maintain public safety.