Optimised detection of copper in rice samples using FAAS and Response Surface Methodology (RSM)

The presence of copper in food samples, particularly rice, poses a significant risk to human health. To date, limited research focuses on the systematic optimisation of these parameters for copper detection in rice using FAAS. This study aimed to optimise the effects of the volume ratio of nitric acid: perchloric acid, heating temperature, and mass of rice in the extraction of copper by using Flame Atomic Absorption Spectrometry (FAAS). The optimisation process was analysed by using a Central Composite Design in Response Surface Methodology (RSM). The optimum condition was determined: volume of nitric acid (6 mL), heating temperature (110 °C), and rice mass (2 g). Under optimised conditions, the copper recovery was approximately in the range of 102.5-113.25%. The limit of detection (LOD) and limit of quantification (LOQ) were estimated at 0.011 μg/mL and 0.038 μg/mL, respectively. Consequently, these concentrations of copper detected in rice samples (Brand A and B) were less than the maximum limits set by who limits.