For the calibration procedure, six different volumes of stock solution were used and the calibration function was constructed for each of the investigated amines by plotting the peak area and respectively peak volume values against the analyte concentration in all cases. The linearity was characterized by the linear range, the regression equation, and the coefficient of determination (R^2). The limit of detection (LOD) and the limit of quantification (LOQ) were calculated using the SMAC (Statistical Methods in Analytical Chemistry) software based on the confidence bands of the calibration function.