江苏典型稻虾及稻蟹共作系统中除草剂残留非靶向动态筛查及污染特征

Dynamic Non-target Analysis and Occurrence of Herbicides Residues in Rice-crayfish and Rice-crab Co-culture Systems in Jiangsu Province

为掌握江苏地区稻虾及稻蟹共作系统内除草剂残留情况,在2种系统内各选择3家典型养殖基地,采用超高效液相色谱-四极杆飞行时间高分辨质谱联用技术(UPLC-Q-TOF MS),对整个养殖周期内虾、蟹和环境(稻田水体、底泥)样品除草剂残留进行动态非靶向筛查,同时,对检出频率高及检出浓度较高的除草剂进行定量分析,结合风险熵(RQ)和混合风险熵(MRQ)进行生态风险评估。结果表明,稻虾和稻蟹共作系统中分别检出12和11种除草剂,其中,灭草隆和氰草津在2种系统中均有检出。稻虾共作系统中主要残留除草剂为喹草酸〔在虾、稻田水和稻田底泥样品中检出频率均较高,最高检出值分别为(12.1±0.17)μg·kg^(-1)、(22.5±2.47)μg·L^(-1)和(21.6±1.91)μg·kg^(-1)〕、敌草隆〔在3种样品中检出频率均较高,最高检出值分别为(11.5±1.10)μg·kg^(-1)、(16.7±1.65)μg·L^(-1)和19.7±0.97μg·kg^(-1)〕、氰草津〔在3种样品中检出频率均较高,最高检出值分别为(11.2±0.36)μg·kg^(-1)、(22.5±3.01)μg·L^(-1)和(29.5±3.20)μg·kg^(-1)〕、绿麦隆〔仅在稻田底泥样品中检出频率较高,最高检出值为(20.1±2.99)μg·kg^(-1)〕和烟嘧磺隆〔仅在稻田底泥样品中检出频率较高,最高检出值为(15.8±1.05)μg·kg^(-1)〕。稻蟹共作系统中主要残留除草剂为双苯酰草胺〔仅在稻田底泥样品中检出频率较高,最高检出值为(20.2±2.05)μg·kg^(-1)〕、禾草丹〔在稻田水和稻田底泥样品中检出频率均较高,最高检出值分别为(11.2±1.01)μg·L^(-1)和(20.1±3.28)μg·kg^(-1)〕、苄嘧磺隆〔仅在稻田底泥样品中检出频率较高,最高检出值为(26.4±3.17)μg·kg^(-1)〕、灭草隆〔在稻田水和稻田底泥样品中检出频率均较高,最高检出值分别为(11.7±2.03)μg·L^(-1)和(20.1±2.64)μg·kg^(-1)〕、2,4-滴丁酯〔仅在稻田底泥样品中检出频率较高,最高检出值为(19.5±2.43)μg·kg^(-1)〕和莠去津〔仅在稻田底泥样品中检出频率较高,最高检出值为(24.7±1.98)μg·kg^(-1)〕。除草剂残留主要集中于环境样品,尤其是在底泥中,而在虾、蟹中残留较少,且残留主要集中于养殖前期,成品收获期检出频次及浓度均较低;虾、蟹总体上处于中风险,而稻田水体及底泥总体上均处于高风险,尤其是稻田底泥检出的11种除草剂,有10种处于高风险(RQ值>1)。江苏典型稻虾及稻蟹共作系统中除草剂污染程度为稻田底泥>稻田水体>虾及蟹,稻田底泥中残留除草剂对周边环境存在潜在生态风险,虾、蟹在收获期除草剂残留风险较小。

To evaluate the herbicides residues in rice-crayfish and rice-crab systems in Jiangsu Province,3 typical breeding bases were selected in these two systems.The dynamic non-target analysis was performed and the occurrence of herbicides residues was tested in biological samples(crayfish and crab)and the environmental samples(field water and field sediment)with ultra-high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry(UPLC-Q-TOF MS)during the culture cycle.Accurate screening and ecological risk assessment of 21 herbicides were conducted through a quantitative analysis with high detection frequency and exposure risk.The results show that 12 and 11 herbicides were detected in the rice-crayfish and rice-crab system,respectively with monuron and cyanazine both detected in the two systems.The main residual herbicides in the rice-crayfish system were quinmerac[the frequency deducted was all relatively high in the crayfish,field water and field sediment samples,with the highest value reached to(12.1±0.17)μg·kg^(-1),(22.5±2.47)μg·L^(-1) and(21.6±1.91)μg·kg^(-1),respectively],diuron[the highest value reached to(11.5±1.10)μg·kg^(-1),(16.7±1.65)μg·L^(-1) and(19.7±0.97)μg·kg^(-1),respectively],cyanazine[the highest values reached to(11.2±0.36)μg·kg^(-1),(22.5±3.01)μg·L^(-1) and(29.5±3.20)μg·kg^(-1),respectively],chlorotoluron[the frequency of detection was only relatively high in the field sediment samples and the highest value reached to(20.1±2.99)μg·kg^(-1)]and nicosulfur[the highest value reached to(15.8±1.05)μg·kg^(-1)].The main residual herbicides in the rice-crab system were benzeneacetamide[the frequency of detection was only relatively high in the field sediment samples and the highest value reached to(20.2±2.05)μg·kg^(-1)],thiobencarb[the frequency of detection were all relatively high in the field water and field sediment samples and the highest values reached to(11.2±1.01)μg·L^(-1) and(20.1±3.28)μg·kg^(-1),respectively],bensulfuron methyl[the highest value reached to(26.4±3.17)μg·kg^(-1)],monuron[the highest values reached to(11.7±2.03)μg·L^(-1) and(20.1±2.64)μg·kg^(-1),respectively],2,4-D-butyl ester[the highest value reached to(19.5±2.43)μg·kg^(-1)]and atrazine[as with the benzeneacetamide and the highest value reached to(24.7±1.98)μg·kg^(-1)].Herbicide residues were mainly detected in environmental samples,especially in field sediment,less in crayfish and crab,and the residues were mainly concentrated in the early stage of aquaculture,and the frequency and value were controllable during the harvest time.The results of this study show that the comprehensive ecological risk of herbicides in crayfish and crab was at medium level,while the risk of field water and field sediment were both at high level,in particular,10 of the 11 herbicides detected in field sediment were in high risk.In this study,it was evident that the herbicides pollution in rice-crayfish and rice-crab systems in Jiangsu Province were in the order of field sediment>field water>aquatic product(crayfish and crab).The results indicate that herbicide residues in field sediment have a potential risk to the aquatic environment,and the risk of herbicide residues pollution to aquatic product(crayfish and crab)is at controllable level during the harvest period.