Detection of Copper, Cadmium, Manganese, Lead, and Zinc Content in Milled Rice Using Microwave Plasma Atomic Emission Spectroscopy

Abstract

This study validated a new method that is not only rapid and cost-effective but also accurate and reliable in the detection of trace metals in rice. The microwave plasma atomic emission spectroscopy (MP-AES) method of tracing elements in rice was validated to quantitatively measure the copper (Cu), manganese (Mn), zinc (Zn), cadmium (Cd), and lead (Pb). Validation that involved precision, accuracy, linearity and dynamic working range, standard addition for matrix effects, limit of detection (LOD), and limit of quantitation (LOQ) showed that the MPAES method was comparable with flame atomic absorption spectroscopy (FAAS) data. The agreement between experimental values from MP-AES and the reference values of CRM 804 gave a very good means of the accuracy of the MP-AES method. The LOQ values achieved were low enough and suitable for detecting trace metals at low levels found in the samples. Thus, the proposed MP-AES method in this work is found to be precise, accurate, sensitive, and reliable. The validated method was applied successfully to rice samples collected from different areas. The MP-AES measurement results showed that trace metals such as Cu, Mn, and Zn were present in 20 rice samples collected from selected provinces of Central Luzon. Therefore, the MP-AES method can be a practical alternative technique to the established method.