3.6. Method validation
In Table 1 the data of the partial validation experiments are shown. A matrix-based calibration curve was obtained by adding standard amounts of MA (from 0.625 to 10 nmols/g) to a sample extract containing MA (1.14 nmol/g). The resulting relationship was Ra = 0.0513 nmol/g + 0.0587 (r2 = 0.995). The slope of this calibration curve, very similar to that obtained using MA aqueous solutions (0.0538), showed a negligible matrix effect in the tested range.