Chlorine and chlorine dioxide treatment to reduce or remove EBDCs and ETU residues in a solution.
Calcium hypochlorite (Ca(OCl)(2)) and chlorine dioxide (ClO(2)), common disinfecting and bleaching chemicals used in the food industry, are potent oxidizing agents. In this paper, the degradation effects of chlorine dioxide on mancozeb and ethylenethiourea (ETU) residues were investigated in a model system and compared with those of liquid chlorine, under various conditions such as differing concentration, pH, reaction time, and temperature. All samples were analyzed for residues by GLC and HPLC. Rate of mancozeb degradation was dependent on pH, with pH 4.6 being the most effective. Mancozeb residues decreased 40-100% with chlorine and chlorine dioxide treatments. ETU residue concentrations in mancozeb solutions were monitored over 60 min. Under controlled conditions, the ETU residue concentrations increased up to 15 min reaction time and then decreased in all three pH ranges. Treatment with both chlorine and chlorine dioxide at pH 4.6, yielded no ETU residues at both 10 and 21 degrees C. The results show that chlorine dioxide gives excellent degradation effects at lower concentrations than liquid chlorine.
Hwang
E
E
Department of Food Science and Human Nutrition, Institute for Environmental Toxicology, Michigan State University, East Lansing, Michigan 48824, USA.
Cash
Jerry N
JN
Zabik
Matthew J
MJ
D017610:Calcium Compounds / Q000737:chemistry / Q000494:pharmacology; D002713:Chlorine / Q000737:chemistry / Q000494:pharmacology*; D017606:Chlorine Compounds / Q000737:chemistry / Q000494:pharmacology*; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D005031:Ethylenethiourea / Q000032:analysis* / Q000737:chemistry; D019649:Food Industry; D005659:Fungicides, Industrial / Q000032:analysis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008344:Maneb / Q000032:analysis* / Q000737:chemistry; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry / Q000494:pharmacology*; D010573:Pesticide Residues / Q000032:analysis* / Q000737:chemistry; D012996:Solutions; D014867:Water; D015038:Zineb / Q000032:analysis* / Q000737:chemistry
D017610:Calcium Compounds; D017606:Chlorine Compounds; D005659:Fungicides, Industrial; D010087:Oxides; D010573:Pesticide Residues; D012996:Solutions; D014867:Water; C004488:calcium hypochlorite; D008344:Maneb; D005031:Ethylenethiourea; D002713:Chlorine; C025109:chlorine dioxide; C013099:mancozeb; D015038:Zineb