Detection of Harmful Metal Elements in Rice Using Laser Induced Breakdown Spectroscopy

Abstract

Transportation of toxic elements from air, water and soil is the main reason for agriculture crops pollution. Therefore, fast detection of heavy metals is very important for ensuring the quality and safety of crops. Laser-induced breakdown spectroscopy (LIBS), coupled with univariate and multivariate analysis, was applied for quantitative analysis of Cr, Pb, Cu and Cd in twelve kinds of rice available in local markets. Qualitative and quantitative analysis of the samples were achieved by using the locally developed LIBS set up equipped with Q-switched Nd: YAG laser and optical spectrum analyzer. Atomic absorption spectrometry (AAS) was used not only to validate the analysis results but also to establish the essential calibration curves. Distribution pattern of detected metals and possible contamination sources were analyzed by radar plot and multivariate statistics including PCA. In this study, harmful metals have been analyzed in all samples. The average content for harmful metals were 0.040 mg/kg for chromium (VI), 0.051 mg/kg for lead, and 0.041 mg/kg for copper and 0.043 mg/kg for cadmium.