Infrared assisted digestion used as a simple green sample preparation method for nutrient analysis of animal feed by microwave induced plasma atomic emission spectrometry.

Based on green analytical chemistry principles it is important to evolve procedures that convert solid samples into solutions without using excessive reagent quantities, energy, temperature, and avoiding waste generation. To reach this aim, a simple infrared assisted digestion (IRAD) method for animal feed analysis was proposed. Infrared radiation (IR) with 2 mL of HNO 3 and 2 mL of H 2 O 2 were assessed, presenting low dissolved organic carbon (DOC) and residual acidity (RA) in the final digest, being fully compatible with microwave induced plasma atomic emission spectrometry (MIP OES). Calcium, Cd, Cu, Fe, K, Mg, Na, P, Sr and Zn were determined in reference materials and in animal feeds. Limits of quantification were between 2.52 and 284 mg kg−1 for Ca and P respectively. Recovery values ranged 80–120%, with relative standard deviations (RSD%) under 8%. The friendliness offered by the IRAD MIP OES method was evaluated by two green indexes. Concentrations in feedstuffs were compared with National Research Council (NRC) recommendations. [Display omitted] • An IRAD MIP OES procedure was developed as efficient green digestion method. • The whole sample treatment procedure could be completed in 30 min for 18 samples. • Ca, Cd, Cu, Fe, K, Mg, Na, P, Sr and Zn were analyzed in animal feed by MIP OES. • The greenness of the development procedure was assessed using two indexes. • The analytical proposed method could be employed for swine feed quality control. [ABSTRACT FROM AUTHOR]