An energy-dispersive X-ray fluorescence method for analysing Fe and Zn in common bean, maize and cowpea biofortification programs

Biofortification breeding programs have the need for rapid and accurate screening methods to identify nutrient dense genotypes. This study explores the use of energy dispersive x-ray fluorescence (EDXRF) for the rapid screening of iron (Fe) and zinc (Zn) concentration in three coarse-grain crops; common bean, maize and cowpea.Bean, maize and cowpea seed was provided from biofortification breeding programs and analysed with Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) to determine reference Fe and Zn concentrations. A subset of samples for each crop was used to calibrate for Zn and Fe and a separate set of samples used to validate the XRF method.Results indicate that when analysing bean, maize and cowpea flour samples, the EDXRF results were not significantly different to the reference ICP-MS analysis, with an average difference of ± 1 mg kg-1 for both Fe and Zn.EDXRF analysis of common beans, cowpea and maize flour enables rapid and accurate analysis when screening for Fe and Zn in bean, maize and cowpea.