Table 1.

Statistical parameters of the two-component FT-IR–ATR model for Vicia faba and Matricaria chamomilla in terms of calibration, validation and external test set validation.

Model	Calibration (n = 21)		validation				External validation
	R2	RMSEE	R2	RMSECV	Bias	RPD	r	RMSEP	RPD	Outlier
Vicia–Matricaria	98.46	3.91	98.04	4.19	±0.50	7.15	0.99	4.43	6.19	0

Model quality is described by coefficient of determination (R²), root mean square error of calibration (RMSEE), root mean square error of cross validation (RMSECV), residual predictive deviation (RPD), correlation coefficient (r), and root mean square error of prediction (RMSEP). Spectra were min–max normalized and the wavenumber region of 3997.3–2185 cm ^-1 and 1823.6–735.4 cm ^-1 were considered. An optimization procedure was used to select the best model (C. Meinen, unpublished data).