Determination of Major Inorganic Nutrients in Maize Tissues by Calibration-Free Laser Induced Breakdown Spectroscopy

Abstract

The quality of the available food is the main issue in the developing countries and maize is one of the commonly used foodstuffs in these countries. Laser-induced breakdown spectroscopy (LIBS) was employed to characterize the presence of the major inorganic nutrients in the maize samples. Each of the samples was shown to contain following elements: K, Ca, Mg, Fe, Na, Si, Li, Sr, Ti, Al, and C while Cr was only detected in the seeds. The electron number density was evaluated by the use of the Stark broadened profile of calcium line and the plasma temperatures have been determined using the Boltzmann plot method. Calibration-free LIBS (CF-LIBS) has been used for the quantitative elemental analysis of the samples. The consistency of the concentrations determined by CF-LIBS was validated using inductively coupled plasma – optical emission spectroscopy (ICP-OES).