Mixed-mode polymeric SPE for the fractionation of acidic and basic combination therapeutics in plasma

摘要

1. We describe a rapid SPE method for the extraction of low concentration levels (0.1 - 500 ng/mL) of amlopodine, atorvastatin and pravastatin from human plasma. The lowest level of quantitation used for a combined extraction and LC-MS-MS method was 0.1 ng/mL (0.5 ng/mL for the acidic compounds). 2. Linearity for all the compounds was good up to three orders of magnitude from 0.5 ng/mL to 500 ng/mL. Correlation coefficients were all above 0.995. Linearity was achieved using no internal standard. (Figures 1, 2, and 3). 3. To demonstrate reproducible results, eight samples were analyzed at high (50 ng/mL) and low concentration (0.5 ng/mL) to determine curve fit with another extracted standard, as well as repeatability over a ten sample set. Recoveries ranged from 87percent to 107percent with RSD values all below 7percent (Figures 1, 2, and 3). 4. Good signal-to-noise ratios were achieved at 0.5 ng/mL for the acidic compounds (Figure 4).