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为探明毒死蜱在梨果实不同部位的残留及消解规律,以20 a生鸭梨(Pyrus bretschneideri Rehd.cv.Yali)为试材,于果实生长期在套袋后向整株喷施48%毒死蜱乳油500倍液(有效成分960 mg/L),分析毒死蜱向果实中的运输及分配规律;于果实成熟期在采收前向果面喷施48%毒死蜱乳油1 000倍液(有效成分480 mg/L),分析采后毒死蜱在梨果实不同组织中的分布特征。采用乙腈萃取和GC-NPD检测方法,测定不同处理试材中的毒死蜱含量。结果表明,在果实套袋情况下,整株喷施毒死蜱后72 h内果实不同部位(果心除外)毒死蜱含量均呈现先逐渐上升而后下降趋势,其中果柄、果皮和果梗洼中毒死蜱最高含量值及其出现的时间分别为6.66 mg/kg(12 h)、2.42 mg/kg(24 h)和0.09 mg/kg(12 h),表明套袋果实毒死蜱来源于枝叶运输,经果柄进入果实后易向果皮累积;而未套袋果施药后24和72 h果皮中毒死蜱含量分别为套袋果的12.56和7.29倍,表明套袋可有效降低果实中毒死蜱的残留量。于果实成熟期向果面喷施毒死蜱后7、14和25d,果皮中毒死蜱残留量分别为15.54、13.70和12.81mg/kg,占全果含量的100%,而果肉中毒死蜱残留量低于本检测方法的最低检出浓度(0.05mg/kg),因此果皮为果实中毒死蜱主要残留部位,且贮藏期果皮中毒死蜱不易向果肉扩散。
In order to find out the residue and digestion law of chlorpyrifos in different parts of pear fruit, 20-year-old Pyrus bretschneideri Rehd.cv.Yali was used as material to spray 48% chlorpyrifos 500 times of EC (active ingredient: 960 mg / L) was used to analyze the transportation and distribution of chlorpyrifos into the fruit. 48% chlorpyrifos EC was sprayed on the fruit surface before harvest / L) to analyze the distribution characteristics of post-harvest chlorpyrifos in different tissues of pear fruit. Acetonitrile extraction and GC-NPD detection methods were used to determine the chlorpyrifos content in different treatments. The results showed that under the condition of bagging, the content of chlorpyrifos in different parts of fruit (excluding fruit heart) increased gradually at first and then decreased after being sprayed with chlorpyrifos for 72 h, and the highest chlorpyrifos in fruit stalk, peel and fruit stem depression The results showed that the contents of chlorpyrifos and bagged fruits were 6.66 mg / kg (12 h), 2.42 mg / kg (24 h) and 0.09 mg / kg (12 h) The fruits were easy to accumulate pericarp. However, the contents of chlorpyrifos in the peels were 12.56 and 7.29 times higher than those of the non-bagged fruits at 24 and 72 h, respectively, indicating that bagging could effectively reduce the residual amount of chlorpyrifos in the fruit. At the fruit ripening stage, the residues of chlorpyrifos in the peel were 15.54, 13.70 and 12.81 mg / kg, respectively, accounting for 100% of the whole fruit at 7, 14 and 25 days after spraying chlorpyrifos on the fruit surface, while the residues of chlorpyrifos in the pulp were lower The detection method of the minimum detectable concentration (0.05mg / kg), so the fruit peel chlorpyrifos is the main residue, and the peel in the peel during storage difficult to spread to the pulp.