Effect of copper ions on the degradation of thiram in aqueous solution: Identification of degradation products by HPLC-MS/MS

JOURNAL OF HAZARDOUS MATERIALS

卷:279

Article

Filipe, Olga M. S.^1,2  Santos, Sonia A. O.³  Domingues, M. Rosario M.⁴  Vidal, Maria. M.^1,2  Silvestre, Armando J. D.³  Santos, Eduarda B. H.⁵ 

[1] Inst Politecn Coimbra, ESAC, DCE, P-3030199 Coimbra, Portugal

[2] Bencanta, CERNAS, P-3040316 Coimbra, Portugal

[3] Univ Aveiro, CICECO, Dept Chem, P-3810193 Aveiro, Portugal

[4] Univ Aveiro, QOPNA, Dept Chem, P-3810193 Aveiro, Portugal

[5] Univ Aveiro, CESAM, Dept Chem, P-3810193 Aveiro, Portugal

关键词: Thiram degradation;    Copper ions;    Dimethyldithiocarbamate;    Aqueous solutions;    UV-vis spectrophotometry;    HPLC-UV-MSn;   

DOI  :  10.1016/j.jhazmat.2014.06.051

来源: Elsevier

【 摘 要 】

The aim of this work was to examine the effect of Cu(II) on the degradation of thiram (Thi) in aqueous solutions, since the literature focused on this effect is scarce and copper based fungicides can be applied together with thiram or during the same season to agricultural crops. The effect of Cu(II) on the degradation of thiram was followed by both UV-vis and HPLC-MS/MS. When thiram is dissolved in pure water its degradation occurs very slowly, being negligible during the first 7 days. However, the presence of Cu(II) has a strong influence on the thiram degradation in aqueous solutions along time. In the presence of an excess of Cu(II), a [CuThi](2+) complex is initially formed which degrades into a complex formed between the dimethyldithiocarbamate anion (DMDTC) and Cu(II) ion, [Cu(DMDTC)](+). This complex further degrades leading to other copper complexes which were identified for the first time, by MSn. The results obtained in the present work also demonstrated that a redox reaction involving DMDTC anions and Cu(II) ions gives rise to the formation of a Thi-Cu(I) complex. Finally, some of the complexes resulting from the degradation of [CuThi](2+) are quite persistent in solution for long periods of time (>1 month). (C) 2014 Elsevier B.V. All rights reserved.

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