采用脂质去除分散固相萃取进行前处理建立鸡蛋中62种农药残留筛查的气相色谱-串联质谱(gas chromatography-tandem mass spectrometry,GC-MS/MS)检测方法。经过条件优化后,样品用10 mL 1%乙酸-乙腈和5 mL水提取,提取液经氯化钠盐析后取...采用脂质去除分散固相萃取进行前处理建立鸡蛋中62种农药残留筛查的气相色谱-串联质谱(gas chromatography-tandem mass spectrometry,GC-MS/MS)检测方法。经过条件优化后,样品用10 mL 1%乙酸-乙腈和5 mL水提取,提取液经氯化钠盐析后取有机相,最后将有机相转移至增强型脂质去除(EMR-Lipid)分散固相萃取净化管中净化并高速离心,GC-MS/MS测定,外标法定量。62种农药在5~400μg/L范围之间线性关系良好,相关系数(R)在0.95以上,其中59种农药的检出限为0.5~5.0μg/kg,定量限为1.0~20.0μg/kg。鸡蛋中62种农药使用EMR-Lipid分散固相萃取净化管去除脂质后的回收率和重复性结果都优于直接经过固相萃取净化管的结果,添加量为100μg/kg时,98.4%的农药平均加标回收率为70.7%~117.2%,相对标准偏差为0.3%~10.9%。基质效应研究表明,62种农药中仅20种农药为弱基质效应,检测结果均需要通过基质标准溶液进行校正。该方法成功应用于实际样品分析。展开更多
In this study,a fluorescent(FL)aptasensor was developed for on-site detection of live Salmonella typhimurium(S.T.)and Vibrio parahaemolyticus(V.P.).Complementary DNA(cDNA)of aptamer(Apt)-functionalized multicolor poly...In this study,a fluorescent(FL)aptasensor was developed for on-site detection of live Salmonella typhimurium(S.T.)and Vibrio parahaemolyticus(V.P.).Complementary DNA(cDNA)of aptamer(Apt)-functionalized multicolor polyhedral oligomeric silsesquioxane-perovskite quantum dots(cDNA-POSSPQDs)were used as encoded probes and combined with dual-stirring-bar-assisted signal amplification for pathogen quantification.In this system,bar 1 was labeled with the S.T.and V.P.Apts,and then bar 2 was functionalized with cDNA-POSS-PQDs.When S.T.and V.P.were introduced,pathogen-Apt complexes would form and be released into the supernatant from bar 1.Under agitation,the two complexes reached bar 2 and subsequently reacted with cDNA-POSS-PQDs,which were immobilized on MXene.Then,the encoded probes would be detached from bar 2 to generate FL signals in the supernatant.Notably,the pathogens can resume their free state and initiate next cycle.They swim between the two bars,and the FL signals can be gradually enhanced to maximum after several cycles.The FL signals from released encoded probes can be used to detect the analytes.In particular,live pathogens can be distinguished from dead ones by using an assay.The detection limits and linear range for S.T.and V.P.were 30 and 10 CFU/mL and 10^(2) -10^(6) CFU/mL,respectively.Therefore,this assay has broad application potential for simultaneous on-site detection of various live pathogenic bacteria in water.展开更多
文摘采用脂质去除分散固相萃取进行前处理建立鸡蛋中62种农药残留筛查的气相色谱-串联质谱(gas chromatography-tandem mass spectrometry,GC-MS/MS)检测方法。经过条件优化后,样品用10 mL 1%乙酸-乙腈和5 mL水提取,提取液经氯化钠盐析后取有机相,最后将有机相转移至增强型脂质去除(EMR-Lipid)分散固相萃取净化管中净化并高速离心,GC-MS/MS测定,外标法定量。62种农药在5~400μg/L范围之间线性关系良好,相关系数(R)在0.95以上,其中59种农药的检出限为0.5~5.0μg/kg,定量限为1.0~20.0μg/kg。鸡蛋中62种农药使用EMR-Lipid分散固相萃取净化管去除脂质后的回收率和重复性结果都优于直接经过固相萃取净化管的结果,添加量为100μg/kg时,98.4%的农药平均加标回收率为70.7%~117.2%,相对标准偏差为0.3%~10.9%。基质效应研究表明,62种农药中仅20种农药为弱基质效应,检测结果均需要通过基质标准溶液进行校正。该方法成功应用于实际样品分析。
基金supported by the National Natural Science Foundation of China(Grant No.:21974074)Ningbo Public Welfare Technology Plan Project of China(Grant Nos.:2021Z056,2022Z170,2022S011,and 202002N3112)+2 种基金Zhejiang Provincial Top Discipline of Biological Engineering(Level A)(Grant Nos.:CX2021051 and KF2021004)Zhejiang Province Public Welfare Technology Application Research Analysis Test Plan(Grant No.:LGC20B 050006)K.C.Wong Magna Fund in Ningbo University.
文摘In this study,a fluorescent(FL)aptasensor was developed for on-site detection of live Salmonella typhimurium(S.T.)and Vibrio parahaemolyticus(V.P.).Complementary DNA(cDNA)of aptamer(Apt)-functionalized multicolor polyhedral oligomeric silsesquioxane-perovskite quantum dots(cDNA-POSSPQDs)were used as encoded probes and combined with dual-stirring-bar-assisted signal amplification for pathogen quantification.In this system,bar 1 was labeled with the S.T.and V.P.Apts,and then bar 2 was functionalized with cDNA-POSS-PQDs.When S.T.and V.P.were introduced,pathogen-Apt complexes would form and be released into the supernatant from bar 1.Under agitation,the two complexes reached bar 2 and subsequently reacted with cDNA-POSS-PQDs,which were immobilized on MXene.Then,the encoded probes would be detached from bar 2 to generate FL signals in the supernatant.Notably,the pathogens can resume their free state and initiate next cycle.They swim between the two bars,and the FL signals can be gradually enhanced to maximum after several cycles.The FL signals from released encoded probes can be used to detect the analytes.In particular,live pathogens can be distinguished from dead ones by using an assay.The detection limits and linear range for S.T.and V.P.were 30 and 10 CFU/mL and 10^(2) -10^(6) CFU/mL,respectively.Therefore,this assay has broad application potential for simultaneous on-site detection of various live pathogenic bacteria in water.
