Gadolinium-Terbium Carbonate Alloy Mixture from Mexico
Specialty mixture of gadolinium and terbium carbonates without cerium, applied in magnetic resonance imaging contrast agents and magneto-optical devices. Classified under HTS 2846.90.80.75 as other rare-earth carbonate mixtures, within inorganic compounds of rare-earth metals per Chapter 28 notes. Chemically defined, excluding radioactive isotopes (2844).
Duty Rate — Mexico → United States
3.7%
Rate breakdown
9903.05.860%Universal product exemption (U.S. note 52(b))
Import Tips
• Ensure NMR purity specs in COA; impurities >1% may reclassify as preparations under 3824
• Radioactivity testing required—confirm <74 Bq/g to avoid 2844 for residues or isotopes
• Partner with licensed customs brokers experienced in Chapter 28 for precise entry summaries