Feasibility Study on the Use of a Portable NIR Spectrometer and Multivariate Data Analysis to Discriminate and Quantify Adulteration in Fertilizer

Table 3

The influence of preprocessing technique on identification models (fertilizer B).

Models	Evaluation	Preprocessing treatment at 5 PCs
		Raw		SNV		FD		SD
		Train	Test	Train	Test	Train	Test	Train	Test
RF	Accuracy	97.50	97.50	97.40	97.40	97.40	97.50	98.00	98.00
	Error rate	2.50	2.50	2.60	2.60	2.60	2.50	2.00	2.00
	Sensitivity	98.10	98.40	98.00	97.50	92.10	91.50	98.00	98.00
	Specificity	99.60	99.60	99.20	99.20	99.60	99.60	99.60	99.60
SVM	Accuracy	98.70	98.70	99.30	99.40	99.50	99.50	99.70	99.40
	Error rate	1.30	1.30	0.70	0.60	0.50	0.50	0.30	0.60
	Sensitivity	98.20	99.50	99.70	99.80	99.50	99.50	99.40	99.60
	Specificity	99.70	99.70	98.60	97.90	97.60	96.80	98.20	97.80