醚菌酯和腐霉利在温室草莓中的残留行为及其膳食摄入风险评估

为明确醚菌酯和腐霉利在温室条件下在草莓中的残留行为及其可能产生的膳食摄入风险,于2012—2013年在北京的日光温室进行了醚菌酯和腐霉利喷施草莓的3次田间农药残留试验,建立了一种快速、简便的气相色谱-质谱联用检测草莓果实中农药残留量的方法,并对不同人群的膳食暴露及风险进行了评估。草莓样品经乙腈提取,PSA(乙二胺-N-丙基硅烷)净化,采用气相色谱分离,四极杆质谱检测,外标法定量。结果表明:醚菌酯和腐霉利在温室草莓中的消解均符合一级动力学方程,醚菌酯为c=0.804 7e-0.114t,R2=0.935 6,半衰期为6.1 d;腐霉利为c=3.283 9e-0.098t,R2=0.927 9,半衰期为7.1 d。当醚菌酯有效成分用量为97.5和195 g/hm2,腐霉利有效成分用量为375和750 g/hm2时,喷药2次和3次,施药间隔期7 d,于末次喷药后1、2、3和5 d采收草莓,其残留量分别在0.09~1.52和0.12~5.81 mg/kg之间。两种药剂的最终残留量均不超过我国规定的最大残留限量(MRL)标准。膳食暴露慢性和急性风险评估结果表明:施药后1~5 d采收的草莓中,醚菌酯和腐霉利对2~6岁、7~14岁、18~30岁和60~70岁的男、女共8类不同人群的膳食摄入风险均在可接受范围之内。

Residue behavior and dietary intake risk assessment of kresoxim-methyl and procymidone in strawberry under greenhouse conditions

To understand the residue behavior and possible dietary intake risk of kresoxim-methyl and procymidone applied to greenhouse grown strawberry(Fragaria ananassa Duch.), residue experiment and dietary intake risk assessment to different populations were carried out at Beijing, China. A simple, rapid analytical method for the determination of fungicide residues in strawberry samples was developed using gas chromatography coupled with mass spectrum detection(GC-MSD). The samples were extracted by acetonitrile,purified on primary secondary amine(PSA), analyzed by the GC-MSD. The target analytes were quantified by external standard method. The solar greenhouse trials were carried for 3 times during 2012-2013.The results indicated that the dissipation rate of the studied fungicides in strawberry fruits samples followed first order kinetics. The dissipation curves were c=0.804 7ｅ-0.114twith half-life of 6.1days for kresoxim-methyl, and c=3.283 9ｅ-0.098t with half-life of 7.1 days for procymidone. The residues in strawberry fruits varied from 0.09-1.52 mg/kg for kresoxim-methyl and 0.12-5.81 mg/kg for procymidone, respectively, when two fungicides were applied with kresoxim-methyl at 97.5 g a.i/hm2 or 195 g a.i/hm2, and procymidone at 375 g a.i/hm2 or 750 g a.i/hm2, spray 2 or 3 times, and 1,2,3,5 d PHI(preharvest interval) were set. The risk assessment adopt the RQ(risk quotient) for chronic risk and RP(risk probability) for acute risk, respectively. The results indicated that the RQ and RP values were below than 1 or 100% for the people age of 2-6, 7-14, 18-30 and 60-70 with 1-5 d PHI, which means the risk to consumers is acceptable.