Study of tea polyphenol as a reversal agent for carcinoma cell lines multidrug resistance (study of TP as a MDR reversal agent)

[11C]Carfentanil was prepared without the need for purification by HPLC. The tetrabutylammonium salt of the precursor carboxylate was reacted with [11C]methyl triflate in DMSO. The resulting [11C]carfentanil was trapped on an Empore extraction disk and washed to remove precursor and most radioactive contaminants. The product was eluted by a small volume of ethanol, mixed with water and passed through a small column containing fibrous anion exchanger to remove remaining radioactive contaminants.