Blood samples were taken at 0.25, 0.5, 1, 2, 4, 6, and 8 h after oral administration of auranofin or aurocyanide (Ott Joslin 2009 (link)). 20 μl of plasma samples were added to 180 μl of acetonitrile containing internal standard, vortexed for 5 min at 15,000 rpm. The supernatants were subjected to LC–MS/MS (Triple Quad 5500, Applied Biosystems, Foster City, CA, USA). Phoenix WinNonlin 6.4 version program (Pharsight Corporation, Mountain View, CA, USA) and non-compartmental analysis model were used for the calculation of pharmacokinetic parameters.