Nicotine sulfate is not commonly available for purchase by the general public due to its highly toxic nature and restricted use. It is primarily used in controlled laboratory settings for research purposes and as an insecticide in certain agricultural applications. Individuals seeking nicotine for vaping or other purposes typically use nicotine in the form of nicotine salts or nicotine solutions, which are safer and more readily available. If you require nicotine sulfate for specific research purposes, you may need to source it from specialized chemical suppliers or contact research institutions that handle such materials. However, it's crucial to handle nicotine sulfate with extreme caution and adhere to all safety guidelines and regulations.