Microwave-Assisted Digestion Using Diluted Nitric Acid for determination of nutrients elements in different waste fruit of agroindustry by inductively coupled plasma optical emission spectrometry (ICP OES)

The current study describes an analytical procedure of microwave-assisted digestion using diluted nitric acid for determination nutrients elements in different waste fruit of agroindustry by inductively coupled plasma optical emission spectrometry (ICP OES). The optimization step was performed using the Doehlert matrix being that the studied variables were nitric acid concentration (2.0 mol L − 1 ) and hydrogen peroxide volume (3.0 mL). The accuracy of the proposed procedure was accessed by analysis of four certified reference material (CRM) of apple leaves (NIST 1515), spinach leaves (NIST 1570a), rice flour (NIST 1568a) and tomato leaves (NIST 1573a). The proposed procedure was successfully applied to the determination of Ca, Mg, K, Na, P, Fe, Zn, Mn and Cu in different waste fruit of agroindustry. Considering some critical parameters such as cost, green chemistry, and analyst safety, the proposed procedure has advantages compared to classical microwave-assisted digestion procedures based on concentrated acids.