1-Methylxanthine from China
1-Methylxanthine is a purine alkaloid metabolite and research chemical with nitrogen-only heterocyclic structure under 2933. Covered by additional U.S. note 3 specifications. Used in biochemical research and pharmaceutical synthesis.
Duty Rate — China → United States
6.5%
Rate breakdown
9903.03.030%Articles the product of any country, as provided for in subdivision (aa)(ii) of U.S. note 2 to this subchapter
Import Tips
• Include NMR or mass spec data confirming structure matches reference standard
• Label as 'research chemical - not for human consumption' to avoid FDA drug scrutiny
• Verify no heavy metal contaminants per USP <232> limits for pharma intermediates