Study of the degradation of the herbicide clomazone in distilled and in irrigated rice field waters using HPLC-DAD and GC-MS

Journal of the Brazilian Chemical Society

Machado, Sérgio L. O.¹  Martins, Manoel L.¹  Zanella, Renato¹  UFSM, Santa Maria, Brazil¹  Primel, Ednei G.¹  Fundação Universidade Federal do Rio Grande, Rio Grande, Brazil¹  Marchesan, Enio¹  Gonçalves, Fábio F.¹  Adaime, Martha B.¹  Universidade Federal de Santa Maria, Santa Maria, Brazil¹ 

关键词: clomazone;    degradation;    HPLC-DAD;    GC-MS;    water;   

DOI  :  10.1590/S0103-50532008000500026

学科分类：化学（综合）

来源: SciELO

【 摘 要 】

This study evaluated the degradation of the herbicide clomazone in distilled water and from irrigated rice fields, through UV irradiation and under natural conditions. After a solid phase extraction (SPE) as preconcentration step, the remained concentration of clomazone was determined by high performance liquid chromatography with diode array detection (HPLC-DAD) and the identification of the degradation products was achieved by gas chromatography-mass spectrometry (GC-MS). Under UV irradiation, the clomazone was degraded faster in distilled water than in surface water. In irrigated rice water, under sunlight irradiation, clomazone presented a half-life time average of 3.2 days in three consecutive harvests, and after application the concentration in water remained higher than 0.1 μg L-1 for 20 days. Several by-products, like 2-chlorobenzaldehyde and 2-chlorobenzene methanol, were identified by GC-MS, which evidenced that the concentration of intermediates at the begining increase and then they also undergo degradation.

【 授权许可】

Unknown