In the synthesis of illegal drugs, law enforcement agencies usually track and combat drug-making activities by monitoring and identifying the following key raw materials. These raw materials have become key regulatory targets due to their irreplaceable nature in synthesis, high consumption or specific uses： --- ### **1. Precursor Chemicals (Precursor Chemicals)** These are the direct raw materials for synthetic drugs, participate in major chemical reactions, and are usually strictly controlled by international conventions (such as the United Nations Drug Control Convention) or national laws.： -**Methamphetamine (crystal meth)**： -**Pseudoephedrine/ephedrine** (extracted from cold medicines, such as some compound preparations). -**Phenylacetone (P2P)**: An alternative raw material for the synthesis path of ephedrine. -*****： -**Morphine** (extracted from opium). -**Acetic anhydride** (used for acetylation of morphine and conversion to heroin). -**Cocaine**： -**Coca leaf** (natural source, but the refining process is monitored). -**Fentanyl synthetic opiate**： -**N-phenethyl-4-piperidone (NPP)**and **4-ANPP** (key precursor). -**isocyanates** (used in the synthesis of carfentanyl, etc.). --- ### **2. Key reagents and solvents** Although it is a common chemical, a large number of abnormal purchases may expose drug-making activities.： -**Reducing agents**: such as red phosphorus and hydroiodic acid (used in meth synthesis). -**Acid/alkali**: such as sulfuric acid, hydrochloric acid, sodium hydroxide (adjust the reaction conditions). -**Organic solvents**: acetone, toluene, diethyl ether (used to extract, crystallize or purify drugs). --- ### **3. Equipment and auxiliary materials** -**Drug-making equipment**: Reactor, tablet press, centrifuge (specific models or bulk purchases are of concern). -**Filter materials**: Activated carbon, filter paper (large purchases may cause suspicion). --- ### **4. Alternative raw materials and "design chemicals”** In order to circumvent regulation, drug makers may use unregulated but functionally similar alternatives： -**Precursor analogs**: For example, use **phenylacetic acid** instead of P2P. -**Non-listed controlled drug intermediates**: Circumvent legal restrictions by adjusting the molecular structure. --- ###**Surveillance methods of law enforcement agencies** 1. **Import, export and supply chain tracking**： -Monitor the international trade in chemicals and focus on verifying the substances listed in the Regulations on the Administration of Easy-to-Make Toxic Chemicals (for example, 38 types of chemicals are listed in China and List I/II chemicals are regulated by the DEA in the United States). -Analyze logistics data and identify abnormal procurement patterns (such as large purchases of specific reagents in remote areas). 2. **Comparison of chemical databases**： -Back-track the source of raw materials through the chemical characteristics of the seized drugs (such as impurities and isotope markers). 3. **On-site forensic evidence**： -Analysis of residual chemicals, reaction vessels and waste in poison-making dens. 4. **Financial and communication monitoring**： -Track the flow of suspicious funds (such as multiple small cash purchases of chemicals). -Analyze chemical procurement discussions in dark web transactions or encrypted communications. 5. **International cooperation and intelligence sharing**： -Share information on the smuggling of precursor chemicals through international organizations (such as INCB). --- ###**Case reference** -**China**: Acetic anhydride is strictly controlled because of its key role in the production of heroin. -**Mexico**: Monitor the flow of liquid ammonia and red phosphorus to combat the manufacture of meth. -**United States**: The DEA focuses on combating the illegal import of fentanyl precursors (such as NPP). Through the above-mentioned means, law enforcement agencies can effectively cut off the supply of raw materials in the drug-making chain and curb the large-scale production of illegal drugs.