Figure 4.

(a) Porcine serum samples (4 mL) with varying amounts of exogenous copper analyzed by ICP-MS before (light gray bars) and after (black bars) addition of PAF-1-SMe. (b) Dose-dependent adsorption of copper by PAF-1-SMe from serum samples. (c) Absorption spectra after addition of 8-hydroxyquinoline to dried PAF-1-SMe with one DMSO wash applied to serum specimens with 0, 2, 5, and 10 ppm of exogenous copper. (inset) Calibration curve showing dependence of absorbance at 410 nm on initial copper concentration for each sample. (d) Comparison of direct copper measurements by ICP-MS (open circles) and calculated copper levels from absorbance at 410 nm using 8-hydroxyquinoline as an indicator (black filled squares).