Determination of elements in cereals, pseudocereals, and legumes by microwave plasma-atomic emission spectrometry

A novel method for multi-element analysis in cereals, pseudocereals, and legumes was developed for principal (calcium, magnesium, potassium, and phosphorus) and trace (manganese, zinc, iron, copper, and aluminum) element determination using a microwave plasma-atomic emission spectrometer (MP-AES). The method was validated using certified reference analyte values from durum wheat (DUWF-1), corn bran (BRAN-1), quinoa (KINO-1), rice (SRM 1568b), and soy (SRM 3234). Spike recoveries were assessed using field-grown crops that represent staple and minor crops with variable matrix compositions. A closed-vessel microwave-assisted digestion method consisting of 12 mL of deionized water, 2 mL of HNO3, and 2 mL of H2O2 was efficient for the mineralization of all crops. Acceptable measurement agreement was achieved between certified and determined values for all reference materials with recovery ranges from 89 to 120 percent. Plant breeders can use the method to develop and screen crops for improved nutrient density.