Development of cost-effective inorganic arsenic extraction method for resource-limited regions: Analysis of efficiency and regulatory implications

This study evaluated the effectiveness of coke and lemonade extraction methods compared to the standard 1 % v/v HNO₃ method for determining inorganic arsenic (iAs) concentrations in rice bran samples using a field-deployable method (Arsenator field kit). The limit of detection (LOD) for the methods was 45 μg kg^-1, comparable to existing literature. The extraction efficiencies were assessed by comparing iAs recovery rates, with coke extraction yielding the highest recovery of 127.4 %, followed by lemonade at 116.2 %, and HNO₃ at 100 %. Statistical analysis indicated strong correlations between the extraction methods, particularly between HNO₃ and coke (Pearson correlation coefficient, 0.990), suggesting that coke extraction is a reliable alternative to the traditional HNO3 method. However, lemonade extraction showed a lower correlation (0.940) and higher false negative rates, indicating potential limitations for regulatory compliance. Notably, at the maximum contaminant limit (MCL) of 0.100 mg kg^-1, coke extraction produced an 8 % false positive rate with no false negatives, while lemonade extraction had an 8 % false positive rate and a 17 % false negative rate. This study underscores the potential of coke extraction as a cost-effective and efficient alternative for assessing iAs levels in rice products, especially in resource-limited settings. Recommendations include the standardization of coke extraction protocols and the development of robust monitoring programs to ensure food safety and public health protection against arsenic contamination. Overall, the findings contribute valuable insights for improving arsenic detection methods and regulatory compliance in food safety practices.