目的:建立高效液相色谱-串联质谱法测定蜂王浆中草甘膦、氨甲基膦酸和N-乙酰草甘膦含量的分析方法。方法:样品经0.2mol/L碳酸氢铵水溶液提取,采用Waters PRIME HLB固相萃取小柱净化,以Dikma Polyamino HILIC色谱柱进行色谱分离,多反应监...目的:建立高效液相色谱-串联质谱法测定蜂王浆中草甘膦、氨甲基膦酸和N-乙酰草甘膦含量的分析方法。方法:样品经0.2mol/L碳酸氢铵水溶液提取,采用Waters PRIME HLB固相萃取小柱净化,以Dikma Polyamino HILIC色谱柱进行色谱分离,多反应监测(MRM)监测模式测定,外标法定量。结果:3种化合物在20~400μg/L的浓度范围内线性关系良好,检出限为20μg/kg,定量限位50μg/kg。空白蜂王浆样品的3水平加标回收率为74.0%~96.1%,相对标准偏差为5.1%~9.6%。结论:该方法适用于蜂王浆中草甘膦及其两种代谢物残留的检测。展开更多
目的建立超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法(ultra performance liquid chromatography-quadrupole electrostatic field orbital trap high resolution mass spectrometry,UPLC-Q-Orbitrap HRMS)测定茶叶中草甘膦、草铵...目的建立超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法(ultra performance liquid chromatography-quadrupole electrostatic field orbital trap high resolution mass spectrometry,UPLC-Q-Orbitrap HRMS)测定茶叶中草甘膦、草铵膦及代谢物的的快速分析方法。方法称取1.00 g茶叶样品,加入20 mL含1%甲酸的甲醇-水(1:1,V:V)提取液,超声提取5 min,4500 r/min离心5 min,经Oasis PRiME HLB固相萃取柱通过式净化,并通过超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法对样品进行测定。结果茶叶中草甘膦、草铵膦及代谢物在5.0~50 ng/mL的范围内,线性关系良好(r 2>0.999),平均回收率在83.7%~92.2%之间,相对标准偏差低于10%,检出限为0.02 mg/kg,定量限为0.05 mg/kg。结论此方法前处理简便快速,且准确性好、灵敏度高,可实现茶叶中草甘膦、草铵膦及其代谢物的快速筛查。展开更多
本研究建立了一种无需衍生化、采用分散固相萃取(d-SPE)结合液相色谱-串联质谱(LC-MS/MS)检测茶叶和花椒中草铵膦及其代谢物NAG和MPPA、草甘膦及其代谢物AMPA残留的方法。样品经10 m L水+10 m L 1%甲酸-甲醇提取后,利用复合型多壁碳纳米...本研究建立了一种无需衍生化、采用分散固相萃取(d-SPE)结合液相色谱-串联质谱(LC-MS/MS)检测茶叶和花椒中草铵膦及其代谢物NAG和MPPA、草甘膦及其代谢物AMPA残留的方法。样品经10 m L水+10 m L 1%甲酸-甲醇提取后,利用复合型多壁碳纳米管(C-MWCNTs)为核心净化材料的d-SPE技术进行处理,以提高目标化合物与基质的分离效率,减少基质干扰,结合液相色谱-串联质谱(LC-MS/MS)检测。以0.7%甲酸溶液和0.7%甲酸-乙腈作流动相,阴离子极性色谱柱(2.1 mm×100 mm,5μm) 40℃分离,负离子模式下动态多反应监测(d MRM),基质外标法定量。结果显示:5种化合物在该仪器条件下峰形尖锐,分离良好,在0.01~2μg/m L范围内线性良好,在茶叶和花椒中的决定系数(R2)分别为R2﹥0.9987和R2﹥0.9992,定量限(LOQ)分别在0.03~0.10 mg/kg之间和0.03~0.16 mg/kg之间。在0.25、0.50、1.0 mg/kg 3个添加水平下,草铵膦、草甘膦及3种代谢物在茶叶(藏茶)中的平均回收率为61%~105%,相对标准偏差(RSD)为0.22%~13%;在花椒(红花椒)中的平均回收率为78%~115%,RSD为0.12%~7.5%。该方法前处理过程无需衍生,净化步骤简单,仪器检测时间短,回收率和精密度均符合方法验证要求,适用于大批量茶叶和花椒中草铵膦、草甘膦及3种代谢物的快速检测。展开更多
Cymbopogon nardus is an invasive grass weed in the grazing lands of Uganda affecting growth of desirable species and impeding movement of livestock. Farmers have for long used manual removal with a hand hoe to control...Cymbopogon nardus is an invasive grass weed in the grazing lands of Uganda affecting growth of desirable species and impeding movement of livestock. Farmers have for long used manual removal with a hand hoe to control the weed to allow growth of palatable species. In order to reduce on the drudgery associated with the hand hoe, a trial was set up to evaluate removal with a hand hoe, use of fire and spraying the weed with glyphosate herbicide to control Cymbopogon nardus. Eight treatments associated with the different control strategies were replicated on four sites in the land use system. Both manual removal with a hand hoe and spraying with glyphosate herbicide were effective in controlling Cymbopogon nardus with 95% and 92% kill of Cymbopogon tussocks, respectively. The differences between the two control methods were not significant. Plant species biodiversity recovery was faster in the manually controlled plots than in those sprayed with glyphosate, but the number of species was not significantly different. The frequency of occurrence of species was however significantly different with manually controlled plots registering a higher frequency of the species. Fire had no effect as a control strategy, but instead increased the number of tussocks, growth vigour of the re-growth, flowering and hence seed setting. After three seasons, no significant difference was observed in species biodiversity between manual and herbicide control. These results suggest that herbicides could effectively be used to control Cymbopogon nardus to cut on costs and avoid the drudgery normally associated with manual control.展开更多
文摘目的:建立高效液相色谱-串联质谱法测定蜂王浆中草甘膦、氨甲基膦酸和N-乙酰草甘膦含量的分析方法。方法:样品经0.2mol/L碳酸氢铵水溶液提取,采用Waters PRIME HLB固相萃取小柱净化,以Dikma Polyamino HILIC色谱柱进行色谱分离,多反应监测(MRM)监测模式测定,外标法定量。结果:3种化合物在20~400μg/L的浓度范围内线性关系良好,检出限为20μg/kg,定量限位50μg/kg。空白蜂王浆样品的3水平加标回收率为74.0%~96.1%,相对标准偏差为5.1%~9.6%。结论:该方法适用于蜂王浆中草甘膦及其两种代谢物残留的检测。
文摘目的建立超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法(ultra performance liquid chromatography-quadrupole electrostatic field orbital trap high resolution mass spectrometry,UPLC-Q-Orbitrap HRMS)测定茶叶中草甘膦、草铵膦及代谢物的的快速分析方法。方法称取1.00 g茶叶样品,加入20 mL含1%甲酸的甲醇-水(1:1,V:V)提取液,超声提取5 min,4500 r/min离心5 min,经Oasis PRiME HLB固相萃取柱通过式净化,并通过超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法对样品进行测定。结果茶叶中草甘膦、草铵膦及代谢物在5.0~50 ng/mL的范围内,线性关系良好(r 2>0.999),平均回收率在83.7%~92.2%之间,相对标准偏差低于10%,检出限为0.02 mg/kg,定量限为0.05 mg/kg。结论此方法前处理简便快速,且准确性好、灵敏度高,可实现茶叶中草甘膦、草铵膦及其代谢物的快速筛查。
文摘本研究建立了一种无需衍生化、采用分散固相萃取(d-SPE)结合液相色谱-串联质谱(LC-MS/MS)检测茶叶和花椒中草铵膦及其代谢物NAG和MPPA、草甘膦及其代谢物AMPA残留的方法。样品经10 m L水+10 m L 1%甲酸-甲醇提取后,利用复合型多壁碳纳米管(C-MWCNTs)为核心净化材料的d-SPE技术进行处理,以提高目标化合物与基质的分离效率,减少基质干扰,结合液相色谱-串联质谱(LC-MS/MS)检测。以0.7%甲酸溶液和0.7%甲酸-乙腈作流动相,阴离子极性色谱柱(2.1 mm×100 mm,5μm) 40℃分离,负离子模式下动态多反应监测(d MRM),基质外标法定量。结果显示:5种化合物在该仪器条件下峰形尖锐,分离良好,在0.01~2μg/m L范围内线性良好,在茶叶和花椒中的决定系数(R2)分别为R2﹥0.9987和R2﹥0.9992,定量限(LOQ)分别在0.03~0.10 mg/kg之间和0.03~0.16 mg/kg之间。在0.25、0.50、1.0 mg/kg 3个添加水平下,草铵膦、草甘膦及3种代谢物在茶叶(藏茶)中的平均回收率为61%~105%,相对标准偏差(RSD)为0.22%~13%;在花椒(红花椒)中的平均回收率为78%~115%,RSD为0.12%~7.5%。该方法前处理过程无需衍生,净化步骤简单,仪器检测时间短,回收率和精密度均符合方法验证要求,适用于大批量茶叶和花椒中草铵膦、草甘膦及3种代谢物的快速检测。
文摘Cymbopogon nardus is an invasive grass weed in the grazing lands of Uganda affecting growth of desirable species and impeding movement of livestock. Farmers have for long used manual removal with a hand hoe to control the weed to allow growth of palatable species. In order to reduce on the drudgery associated with the hand hoe, a trial was set up to evaluate removal with a hand hoe, use of fire and spraying the weed with glyphosate herbicide to control Cymbopogon nardus. Eight treatments associated with the different control strategies were replicated on four sites in the land use system. Both manual removal with a hand hoe and spraying with glyphosate herbicide were effective in controlling Cymbopogon nardus with 95% and 92% kill of Cymbopogon tussocks, respectively. The differences between the two control methods were not significant. Plant species biodiversity recovery was faster in the manually controlled plots than in those sprayed with glyphosate, but the number of species was not significantly different. The frequency of occurrence of species was however significantly different with manually controlled plots registering a higher frequency of the species. Fire had no effect as a control strategy, but instead increased the number of tussocks, growth vigour of the re-growth, flowering and hence seed setting. After three seasons, no significant difference was observed in species biodiversity between manual and herbicide control. These results suggest that herbicides could effectively be used to control Cymbopogon nardus to cut on costs and avoid the drudgery normally associated with manual control.
