Testing the purity of street drugs usually requires specialized equipment and techniques. However, there are some simple methods that can provide a preliminary assessment of the purity of drugs, but these methods are not completely reliable. Here are some common methods: 1. **Color reagent test**: There are reagents available on the market (such as Marquis, Mecke, Mandelin, etc.) that can determine the composition and purity by reacting with the drug to produce a specific color. This requires some chemical knowledge and should be used with caution. 2. **Simple instrument detection**: Some portable detection devices can detect drug components in non-laboratory environments, such as infrared spectrometers, but the price is usually high and professional knowledge is required to interpret the results. 3. **Observation and feeling**: By observing the characteristics of the drug such as appearance, smell and taste, some preliminary information can be obtained, but this method is very unreliable and prone to misjudgment. 4. **Seek professional testing**: If accurate results are required, it is best to send the sample to a professional laboratory for testing. Many places offer anonymous and guilt-free testing services. Please note that possession or use of drugs is illegal in many places, and participating in related activities may have legal risks. At the same time, the use of such substances itself may also cause serious health hazards. It is recommended to act within the premise of legality and safety, and pay attention to personal health and safety.