Extraction Behaviors for Inorganic Arsenic Removal from Seaweed (Gracilaria Fisheri) Using Food Additives

The extraction behaviors for inorganic arsenic removal under batch system using food additives at actual pH with other conditions, concentration, extraction volume, and extraction time were studied. In batch extraction, 100 rpm orbital shaker speed at room temperature was held constant. The results showed that EDTA was the most effective extractant for inorganic arsenic removal. Afterward, with the increase of EDTA concentration, at 0.10 M, inorganic arsenic removal increased to reach 100% extraction efficiency. Batch extraction using 0.10 M EDTA at the volume of 75 mL for 120 min shaking was optimal giving the highest extraction efficiency, up to 98%. Under optimized conditions, the amounts of arsenic in real seaweed samples were reduced from 4.60 ± 0.15 to 0.09 ± 0.01 mg kg−1-dry weight, lower than that of standard levels of community seaweed product. Therefore, these results provided strong evidence of the promising procedure for arsenic removal from Gracilaria fisheri seaweed by batch extraction.