Residues of 14C- carbofuran were studied in model late- rice ecosystem (LRE) and early- rice ecosystem (ERE). The treatment consisted of two rates of the pesticide (1x) and 2.5x). At day 56 after application, 7.3% (1x...Residues of 14C- carbofuran were studied in model late- rice ecosystem (LRE) and early- rice ecosystem (ERE). The treatment consisted of two rates of the pesticide (1x) and 2.5x). At day 56 after application, 7.3% (1x) and 2.9% (2.5x) of the pesticide and its degradative products remained in the water of the LRE, and 1.8% (1x) and 2.4% (2.5x) of them remained in the water of the ERE. At harvest, 37.5% (LRE) and 24.0% (ERE) of the pesticide applied were detected in the upper layer of the soil; and 40.6% (LRE) and 26.9% (ERE) remained in the lower layer of the soil. The residues in the rice plants increased at the first stage, reached maximum levels during day 14 to 28 after application, and decreased thereafter. At harvest, residues in the stems and leaves in the two treatments (1x and 2.5x) were 3.91μ g/g and 7.78μ g/g (LRE) and 5.04 μg/g and 17.29 μ g/g (ERE) respectively. Residues in the ears were about 1/8 to 1/12 of that in the other parts of the plants. The pesticide residues in fish bodies in both experiments were also determined.展开更多
目的建立一种在线凝胶色谱-气相色谱-质谱(gel permeation chromatography coupled with gas chromatography-mass spectrometry,GPC-GC/MS)联用法测定淡水鱼中农药残留的检测方法。方法采用超声辅助技术和高效萃取吸管法对南昌地区淡...目的建立一种在线凝胶色谱-气相色谱-质谱(gel permeation chromatography coupled with gas chromatography-mass spectrometry,GPC-GC/MS)联用法测定淡水鱼中农药残留的检测方法。方法采用超声辅助技术和高效萃取吸管法对南昌地区淡水鱼样品净化处理,以乙腈为提取液,采用氯化钠去除水分后,经在线GPC-GC-MS系统进样分析,选择离子检测方式定量检测。结果25种化合物的质量浓度在一定范围内与其对应的峰面积有良好的线性关系,相关系数大于0.996,方法的检出限为9.1×10^-5-3.1×10^-1mg/kg。以空白样品为基体进行加标回收实验,回收率为71.4%~103.2%,相对标准偏差小于9%。结论该方法前处理简单快速,灵敏度高,有机溶剂使用量少,适用于淡水鱼中农药残留的检测。展开更多
研究超声波提取法提取桔梗中残留的克百威农药,探讨了提取时间、提取温度和所加溶剂量对克百威提取率的影响,并通过正交设计对桔梗中药的克百威提取条件进行优化.结果表明提取温度、提取时间和溶剂量对克百威的提取均有显著影响.通过方...研究超声波提取法提取桔梗中残留的克百威农药,探讨了提取时间、提取温度和所加溶剂量对克百威提取率的影响,并通过正交设计对桔梗中药的克百威提取条件进行优化.结果表明提取温度、提取时间和溶剂量对克百威的提取均有显著影响.通过方差分析,确定其影响因素的大小顺序是提取温度>提取时间>溶剂量.最优提取条件为温度40℃、丙酮溶剂量30 m L、提取时间30 min.展开更多
目的建立一种克百威及3-羟基克百威农药残留的液相色谱-串联质谱(liquid chromatographytandem mass spectrometry,LC-MS/MS)检测方法。方法样品经乙腈提取,氯化钠盐析除水后,过氨基固相萃取柱净化,甲醇和二氯甲烷混合溶液洗脱。采用0.1...目的建立一种克百威及3-羟基克百威农药残留的液相色谱-串联质谱(liquid chromatographytandem mass spectrometry,LC-MS/MS)检测方法。方法样品经乙腈提取,氯化钠盐析除水后,过氨基固相萃取柱净化,甲醇和二氯甲烷混合溶液洗脱。采用0.1%甲酸(A)和0.1%甲酸-乙腈(B)作为流动相进行梯度洗脱,质谱(ESI+)采用多离子检测模式(MRM)对定量离子和定性离子进行监测。结果本方法在15 min内完成2种目标化合物的分离分析。克百威和3-羟基克百威在10、30和100μg/kg添加水平的回收率为72.0%~106.4%,相对标准偏差小于6.9%(n=6),方法定量限为10μg/kg。结论该方法快速、准确、灵敏,适合测定蔬菜中克百威及3-羟基克百威药物残留。展开更多
基金Research carried out with the support of IAEA under Research Contract No. 4233/RB
文摘Residues of 14C- carbofuran were studied in model late- rice ecosystem (LRE) and early- rice ecosystem (ERE). The treatment consisted of two rates of the pesticide (1x) and 2.5x). At day 56 after application, 7.3% (1x) and 2.9% (2.5x) of the pesticide and its degradative products remained in the water of the LRE, and 1.8% (1x) and 2.4% (2.5x) of them remained in the water of the ERE. At harvest, 37.5% (LRE) and 24.0% (ERE) of the pesticide applied were detected in the upper layer of the soil; and 40.6% (LRE) and 26.9% (ERE) remained in the lower layer of the soil. The residues in the rice plants increased at the first stage, reached maximum levels during day 14 to 28 after application, and decreased thereafter. At harvest, residues in the stems and leaves in the two treatments (1x and 2.5x) were 3.91μ g/g and 7.78μ g/g (LRE) and 5.04 μg/g and 17.29 μ g/g (ERE) respectively. Residues in the ears were about 1/8 to 1/12 of that in the other parts of the plants. The pesticide residues in fish bodies in both experiments were also determined.
文摘目的建立一种在线凝胶色谱-气相色谱-质谱(gel permeation chromatography coupled with gas chromatography-mass spectrometry,GPC-GC/MS)联用法测定淡水鱼中农药残留的检测方法。方法采用超声辅助技术和高效萃取吸管法对南昌地区淡水鱼样品净化处理,以乙腈为提取液,采用氯化钠去除水分后,经在线GPC-GC-MS系统进样分析,选择离子检测方式定量检测。结果25种化合物的质量浓度在一定范围内与其对应的峰面积有良好的线性关系,相关系数大于0.996,方法的检出限为9.1×10^-5-3.1×10^-1mg/kg。以空白样品为基体进行加标回收实验,回收率为71.4%~103.2%,相对标准偏差小于9%。结论该方法前处理简单快速,灵敏度高,有机溶剂使用量少,适用于淡水鱼中农药残留的检测。
文摘研究超声波提取法提取桔梗中残留的克百威农药,探讨了提取时间、提取温度和所加溶剂量对克百威提取率的影响,并通过正交设计对桔梗中药的克百威提取条件进行优化.结果表明提取温度、提取时间和溶剂量对克百威的提取均有显著影响.通过方差分析,确定其影响因素的大小顺序是提取温度>提取时间>溶剂量.最优提取条件为温度40℃、丙酮溶剂量30 m L、提取时间30 min.
文摘目的建立一种克百威及3-羟基克百威农药残留的液相色谱-串联质谱(liquid chromatographytandem mass spectrometry,LC-MS/MS)检测方法。方法样品经乙腈提取,氯化钠盐析除水后,过氨基固相萃取柱净化,甲醇和二氯甲烷混合溶液洗脱。采用0.1%甲酸(A)和0.1%甲酸-乙腈(B)作为流动相进行梯度洗脱,质谱(ESI+)采用多离子检测模式(MRM)对定量离子和定性离子进行监测。结果本方法在15 min内完成2种目标化合物的分离分析。克百威和3-羟基克百威在10、30和100μg/kg添加水平的回收率为72.0%~106.4%,相对标准偏差小于6.9%(n=6),方法定量限为10μg/kg。结论该方法快速、准确、灵敏,适合测定蔬菜中克百威及3-羟基克百威药物残留。
