You can purchase pure nicotine that meets USP (United States Pharmacopeia) or EP (European Pharmacopoeia) standards, typically from specialized chemical suppliers or online retailers. These products are often labeled as "Pure Nicotine USP/EP 99+" to indicate their high purity level, usually 99% or higher. When buying pure nicotine, ensure that you're sourcing it from reputable suppliers who provide proper handling instructions and adhere to safety regulations. Additionally, be aware of any legal requirements or restrictions regarding the purchase and use of pure nicotine in your location.