title: Radiolytic degradation of herbicide 4-chloro-2-methyl phenoxyacetic acid (MCPA) by gamma-radiation for environmental protection.
abstract: Reversed-phase HPLC determination of the herbicide MCPA and its products of radiolytic degradation has been optimized. The radiolytic degradation was carried out using gamma-irradiation and was optimized in terms of irradiation dose and pH of irradiated MCPA solution. Decomposition of 100 ppm MCPA in pure solutions required irradiation with a 3 kGy dose. The main products of irradiation in the dose range up to 10-kGy were various phenolic compounds and carboxylic acids. The developed method was applied for treatment of industrial waste from production of MCPA. The 10-kGy dose was needed for decomposition of 500 ppm of MCPA in the industrial waste samples; however, the presence of stoichiometric amount of hydrogen peroxide in the irradiated waste allowed a 50% reduction of the gamma-irradiation dose. Despite complete decomposition of MCPA in the industrial waste, in order to reduce the toxicity of irradiated waste, measured by the Microtox bioluminescence test, higher than a 10 kGy irradiation dose was needed.
authors.affiliation: Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Bojanowska-Czajka
authors.forename: Przemysław
authors.initials: P
authors.lastname: Drzewicz
authors.forename: Czesław
authors.initials: C
authors.lastname: Kozyra
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Nałecz-Jawecki
authors.forename: Józef
authors.initials: J
authors.lastname: Sawicki
authors.forename: Bogdan
authors.initials: B
authors.lastname: Szostek
authors.forename: Marek
authors.initials: M
authors.lastname: Trojanowicz
mesh_terms: D008456:2-Methyl-4-chlorophenoxyacetic Acid / Q000032:analysis / Q000528:radiation effects*; D002851:Chromatography, High Pressure Liquid; D005720:Gamma Rays; D006540:Herbicides / Q000032:analysis / Q000528:radiation effects*; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000032:analysis*; D011829:Radiation Dosage; D012996:Solutions; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D006540:Herbicides; D007220:Industrial Waste; D012996:Solutions; D006861:Hydrogen Peroxide; D008456:2-Methyl-4-chlorophenoxyacetic Acid