Method for detection and removal of arsenic residues in calcium carbide ripened mangoes

Abstract

Arsine (AsH3) and phosphine (PH3) present in calcium carbide (CaC2) as impurities might find entry in the calcium carbide ripened fruits. To evaluate the presence of harmful arsenic residues in traditionally ripened fruits, different combinations of calcium carbide were evaluated for arsenic level and compared with market samples and mango ripened without calcium carbide. Among different combinations, CaC2 ripened fruits contained harmful arsenic (As) between 34.73 and 73.43 ppb as compared to high residue in open market mangoes (106.27 ppb), while fruits ripened without CaC2 did not contain this residue. Further, dipping fruit in 2% Na2CO3 or 2% agri-biosoft solution for 12 hr was effective in reducing the arsenic residue from 71.02 ppb to 6.74–9.05 ppb from fruit surface and also removes arsenic from peel and pulp. Thus, presence of arsenic residue on the ripened mangoes can be used as a tool for detecting use of CaC2 in ripening and use of 2% Na2CO3 or 2% agri-biosoft solution for removal of arsenic from ripened fruits. Practical applications A technique was developed for detection and removal of harmful arsenic residues in mangoes traditionally ripened by using banned calcium carbide. Detection of arsenic residue can be used as the technique to detect the use of calcium carbide for ripening of mangoes in the fruit lot. Dipping mangoes in 2% sodium carbonate solution for 12 hr can be used to remove arsenic residues from the calcium carbide ripened mangoes prior to their consumption.