2.5.1. Linearity

The linearity of the method was determined the seven calibration standards in the 33 different runs. The linear calibration curve was generated by plotting the ratio of the peak area of the detected versus the spiked concentrations. A weighing of 1/x was used. The correlation of the measured results and the target values represents the accuracy of this standard level and needs to be <15% following the CLSI EP06 guideline. The method was accepted as being linear within the 95% confidence interval. The slope and intercept did not deviate from 1 and 0, respectively with a certainty of p < 0.05. Calculations were made by using the Passing Bablok regression, Spearmans correlation and the Bland-Altman test.