A procedure for the determination of trace metals in rice varieties using microwave induced plasma atomic emission spectrometry

In this study, a practical procedure was described to determine various elements in different rice samples using microwave induced plasma atomic emission spectrometry (MP AES). Prior to analysis, rice samples were dried and grinded. The powdered rice samples and standard reference material were weighted around 0.1 g and digested with 10 mL of HNO₃ till clear digests were obtained. To prevent clogging of torch, digests then filtered and then directly introduced to the plasma of MP AES. All determinations were performed using aqueous standards for calibration. The analytes in certified reference material (IRMM 804 Rice Flour and NCS ZC 73030 Wheat) were determined in the uncertainty limits of the certified values as well as the analytes added to the samples prior to digestion were recovered quantitatively (>90%). No spectral interference was detected at the working wavelengths of the analytes. Finally, the analyte concentrations in various types of rice samples were determined.