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

Table 1

Samples used for the experiment.

No.	Categories	Fertilizer type	No. of samples	Percentage purity (%)	Chemical	Physical
Brand A	Authentic = A	Improved urea	63	100	40% N + 5.6% S	Nitrogen sulphate sulphur granular fertilizer that is 100% soluble
	Expired = A	Improved urea	63	100	40% N + 5.6% S
	Adulterated = A	Improved urea	35	10	Nil	Pure improved urea samples adulterated with expired ones
			35	20
			35	30
			35	40
			35	50
Brand B	Authentic = B	Nitrabor	63	100	15.4% N + 25.9% CaO + 0.3% B	Dense granular field grade calcium nitrate fertilizer
	Expired = B	Nitrabor	63	100	15.4% N + 25.9% CaO + 0.3% B
	Adulterated = B	Nitrabor	35	10	Nil	Pure nitrabor samples adulterated with expired ones
			35	20
			35	30
			35	40
			35	50
	Total samples		602