目的:基于QuEChERS方法结合气相色谱串联质谱(Gas Chromatography-Tandem Mass Spectrometry,GC-MS/MS)技术,建立一种简单、快速检测果蔬中农药残留的方法。方法:果蔬样品匀浆后,先用乙腈和乙酸缓冲盐包提取,再用m-PFC小柱净化,最后用GC...目的:基于QuEChERS方法结合气相色谱串联质谱(Gas Chromatography-Tandem Mass Spectrometry,GC-MS/MS)技术,建立一种简单、快速检测果蔬中农药残留的方法。方法:果蔬样品匀浆后,先用乙腈和乙酸缓冲盐包提取,再用m-PFC小柱净化,最后用GC-MS/MS测定,外标法定量。结果:13种农药在10~500μg·L^(-1)浓度范围内线性关系良好,相关系数(R^(2))均大于0.994,检出限为0.35~0.92μg·kg^(-1),定量限为1.0~2.8μg·kg^(-1);13种农药在3个水平下的加标回收率为82.4%~110.1%,相对标准偏差为2.9%~9.3%。结论:所建立的方法可操作性强,具有较高的精密度和准确度,可用于果蔬中农药残留的定性和定量检测。展开更多
针对6种欧盟及日本进出口果蔬中重点检测,但在我国食品安全国家标准中暂无检测标准的农药物质进行研究,建立一种改进的QuEChERS(Quick,Easy,Cheap,Effective,Rugged and Safe)提取净化方法结合气相色谱-串联质谱技术(Gas Chromatography...针对6种欧盟及日本进出口果蔬中重点检测,但在我国食品安全国家标准中暂无检测标准的农药物质进行研究,建立一种改进的QuEChERS(Quick,Easy,Cheap,Effective,Rugged and Safe)提取净化方法结合气相色谱-串联质谱技术(Gas Chromatography-tandem Mass Spectrometry,GC-MS/MS)检测方法,能快速检测叶菜类蔬菜基质中邻苯基苯酚钠、二甲基敌草索等6种农药多残留。样品采用乙腈提取、无水MgSO4与NaCl盐析除水后,经N-丙基乙二胺(PSA)固相材料净化,使用GC-MS/MS在多反应监测模式(Multi Reaction Monitoring,MRM)下分析检测。结果表明:6种农药物质在0.002~0.5μg/mL范围内线性关系良好,相关系数R均大于0.998,方法检出限(RSN=3)为0.15~2.32μg/kg,平均回收率为84.50%~106.23%,相对标准偏差为0.96%~8.35%,此结果均符合欧盟农药残留分析质量控制程序要求与日本和欧盟对农残“一律标准”中农药限量要求。将建立的检测方法应用于其他蔬菜中高发农药物质的检测,检测效果良好。该方法重复性好、耗时短、易操作,为邻苯基苯酚钠、二甲基敌草索等多种农药残留的检测提供了新的检测技术和依据。展开更多
Background:Soil acidifcationn caused by anthropogenic activities may aft soil biochemical cydling,bidiversity,productivity,and multiple eosystem-related functions in drylands.However,to date,such information is lackin...Background:Soil acidifcationn caused by anthropogenic activities may aft soil biochemical cydling,bidiversity,productivity,and multiple eosystem-related functions in drylands.However,to date,such information is lacking to support this hypothesis.Methods Based on a transect survey of 78 naturally assembled shrub communities,we caloulated acid deposition flux in Northwest China and evaluated its likely ecological ffets by testing three altemnative hypotheses,namely:.nidche complementarity,mass ratio,and vegetation quantity hypotheses Rao's quadratic entopy and community-weighted mean traits were employed to represent the complementary aspect of niche complementarity and mass ratio effects,respectively.Resulbs:We observed that in the past four decades,the concentrations of exchangeable base cations in soil in Northwest China have decreased significantly to the extent of having faced the risk of depletion,whereas changes in the calium carbonate content and pH of soil were not significant.Adid deposition primani ly increased the aboweground biomass and shrub density in shrublands but had no sigmificant effect on shrub richness and ecasystem multifunctionality(EMF),indicating that acid deposition had positive but weak ecological effects on dryland ecosystems.Community wd ghted mean of functional traits(representing the mass ratio hypothesis)correlated negatively with EMF,whereas both Rao's quadratic entropy(representing the niche complementarity hypothesis)and aboveground biomass(representing the vegetation quantity hypothesis)correlated positively but insignifcantly with EMF.These biodiversity-EMF relationships highlight the fragility and instability of drylands relative to forest ecasystems.Concuions:The findings from this study serve as important reference points to understand the ris of soil acidification in arid regions and its impacts on biodiversity-EMF relationships.展开更多
目的基于高效液相色谱-四极杆-飞行时间质谱法(high performance liquid chromatography quadrupole time of flight mass spectrometry,LC-QTOF/MS)建立蔬菜中124种药物和个人护理品(pharmaceuticals and personal care products,PPCPs...目的基于高效液相色谱-四极杆-飞行时间质谱法(high performance liquid chromatography quadrupole time of flight mass spectrometry,LC-QTOF/MS)建立蔬菜中124种药物和个人护理品(pharmaceuticals and personal care products,PPCPs)的同时快速筛查、确证和定量分析方法。方法样品经过10 m L乙腈提取,改进QuEChERS方法净化,电喷雾电离模式,外标法定量;建立一级精确质量数据库、色谱保留时间和二级质谱库,实现蔬菜中124种目标污染物的快速筛查和确证。结果在5~500μg/L质量浓度范围内,124种目标化合物的线性关系良好(r>0.99)。多种蔬菜基质中10、50、200μg/kg的3个加标水平下平均回收率为62.7%~117.2%,相对标准偏差为1.6%~8.9%。满足痕量分析要求,基质干扰效应消除效果较好,该方法具有良好的净化效果。结论该方法具有操作简便;耗时短;灵敏度高;稳定性好的优点,适用于蔬菜基质中PPCPs的筛查检测及定量分析,对蔬菜质量安全的快速筛查具有技术支撑意义。展开更多
文摘目的:基于QuEChERS方法结合气相色谱串联质谱(Gas Chromatography-Tandem Mass Spectrometry,GC-MS/MS)技术,建立一种简单、快速检测果蔬中农药残留的方法。方法:果蔬样品匀浆后,先用乙腈和乙酸缓冲盐包提取,再用m-PFC小柱净化,最后用GC-MS/MS测定,外标法定量。结果:13种农药在10~500μg·L^(-1)浓度范围内线性关系良好,相关系数(R^(2))均大于0.994,检出限为0.35~0.92μg·kg^(-1),定量限为1.0~2.8μg·kg^(-1);13种农药在3个水平下的加标回收率为82.4%~110.1%,相对标准偏差为2.9%~9.3%。结论:所建立的方法可操作性强,具有较高的精密度和准确度,可用于果蔬中农药残留的定性和定量检测。
文摘针对6种欧盟及日本进出口果蔬中重点检测,但在我国食品安全国家标准中暂无检测标准的农药物质进行研究,建立一种改进的QuEChERS(Quick,Easy,Cheap,Effective,Rugged and Safe)提取净化方法结合气相色谱-串联质谱技术(Gas Chromatography-tandem Mass Spectrometry,GC-MS/MS)检测方法,能快速检测叶菜类蔬菜基质中邻苯基苯酚钠、二甲基敌草索等6种农药多残留。样品采用乙腈提取、无水MgSO4与NaCl盐析除水后,经N-丙基乙二胺(PSA)固相材料净化,使用GC-MS/MS在多反应监测模式(Multi Reaction Monitoring,MRM)下分析检测。结果表明:6种农药物质在0.002~0.5μg/mL范围内线性关系良好,相关系数R均大于0.998,方法检出限(RSN=3)为0.15~2.32μg/kg,平均回收率为84.50%~106.23%,相对标准偏差为0.96%~8.35%,此结果均符合欧盟农药残留分析质量控制程序要求与日本和欧盟对农残“一律标准”中农药限量要求。将建立的检测方法应用于其他蔬菜中高发农药物质的检测,检测效果良好。该方法重复性好、耗时短、易操作,为邻苯基苯酚钠、二甲基敌草索等多种农药残留的检测提供了新的检测技术和依据。
基金financially supported by the third xinjiang scientific expedition program (grant no.2022xjkk0901)the Strategic Priority Research Program of Chinese Academy of Sciences (No.XDA2006030102)the National Natural Sciences Foundation of China(No.42171068 and No.42330503)。
文摘Background:Soil acidifcationn caused by anthropogenic activities may aft soil biochemical cydling,bidiversity,productivity,and multiple eosystem-related functions in drylands.However,to date,such information is lacking to support this hypothesis.Methods Based on a transect survey of 78 naturally assembled shrub communities,we caloulated acid deposition flux in Northwest China and evaluated its likely ecological ffets by testing three altemnative hypotheses,namely:.nidche complementarity,mass ratio,and vegetation quantity hypotheses Rao's quadratic entopy and community-weighted mean traits were employed to represent the complementary aspect of niche complementarity and mass ratio effects,respectively.Resulbs:We observed that in the past four decades,the concentrations of exchangeable base cations in soil in Northwest China have decreased significantly to the extent of having faced the risk of depletion,whereas changes in the calium carbonate content and pH of soil were not significant.Adid deposition primani ly increased the aboweground biomass and shrub density in shrublands but had no sigmificant effect on shrub richness and ecasystem multifunctionality(EMF),indicating that acid deposition had positive but weak ecological effects on dryland ecosystems.Community wd ghted mean of functional traits(representing the mass ratio hypothesis)correlated negatively with EMF,whereas both Rao's quadratic entropy(representing the niche complementarity hypothesis)and aboveground biomass(representing the vegetation quantity hypothesis)correlated positively but insignifcantly with EMF.These biodiversity-EMF relationships highlight the fragility and instability of drylands relative to forest ecasystems.Concuions:The findings from this study serve as important reference points to understand the ris of soil acidification in arid regions and its impacts on biodiversity-EMF relationships.
文摘目的基于高效液相色谱-四极杆-飞行时间质谱法(high performance liquid chromatography quadrupole time of flight mass spectrometry,LC-QTOF/MS)建立蔬菜中124种药物和个人护理品(pharmaceuticals and personal care products,PPCPs)的同时快速筛查、确证和定量分析方法。方法样品经过10 m L乙腈提取,改进QuEChERS方法净化,电喷雾电离模式,外标法定量;建立一级精确质量数据库、色谱保留时间和二级质谱库,实现蔬菜中124种目标污染物的快速筛查和确证。结果在5~500μg/L质量浓度范围内,124种目标化合物的线性关系良好(r>0.99)。多种蔬菜基质中10、50、200μg/kg的3个加标水平下平均回收率为62.7%~117.2%,相对标准偏差为1.6%~8.9%。满足痕量分析要求,基质干扰效应消除效果较好,该方法具有良好的净化效果。结论该方法具有操作简便;耗时短;灵敏度高;稳定性好的优点,适用于蔬菜基质中PPCPs的筛查检测及定量分析,对蔬菜质量安全的快速筛查具有技术支撑意义。
