Table 2.

Calibration statistics for beans, cowpea and maize for Oxford Instruments and Bruker XRF instruments

Species	Analyte	Range (mg kg–1)	Mean (mg kg–1)	Sample no.	Oxford Instruments		Bruker
					r2	SEC (mg kg–1)	r2	SEC (mg kg–1)
Bean	Fe	50.2–91.6	68.4	24	0.96	±2.4	0.96	± 2.8
	Zn	22.5–44.5	31.1	24	0.92	± 1.7	0.92	±1.1
Cowpea	Fe	46.4–94.5	65.4	25	0.94	± 2.6	0.94	± 2.9
	Zn	25.9–62.2	43.4	25	0.96	± 2.6	0.98	±1.5
Maize	Fe	11.6–31.0	20.2	23	0.90	±1.9	0.92	±1.5
	Zn	16.8–38.6	26.6	23	0.92	± 2.1	0.95	±1.5