Comparison of quinidine by fluorescence polarization immunoassay and high pressure liquid chromatography

Analysis of quinidine was performed using fluorescence polarization immunoassay (Abbott TDXTM) with an ion-pairing adsorption high pressure liquid chromatography (HPLC) technique as the comparative method. Correlation of 110 clinical samples was excellent (r2 = 0.983). TDX calibration appeared stable for 14 days. There is minimal contribution to the concentration of quinidine due to the presence of metabolite. The TDX method is rapid, precise, and accurate.