Fig. 2.

Passing-Bablok regression analysis of the enzymatic method compared to LC-MS. Comparison using plasma samples with MPA concentrations >0.4 mg/L (Fig. 2a) or with MPA concentrations within the linearity range of the enzymatic method (0.4–15 mg/L) (Fig. 2b). The full line is the regression-line. The two dashed lines show the 95% confidence interval and the point line is slope=1.