This article presents the designing and fabrication of a microfluoidic chip with an integrated supported-liquid-membrane extraction-back-extraction and chip-based capillary electrophoresis system(SLMEBE-CCE).A 3-dimen...This article presents the designing and fabrication of a microfluoidic chip with an integrated supported-liquid-membrane extraction-back-extraction and chip-based capillary electrophoresis system(SLMEBE-CCE).A 3-dimensional channel network for the SLMEBE-CCE system was fabricated with a four-layer glass/PTFE-membrane hybrid structure. With a gravity pump for sample and back-extraction solution delivery and a multi-channel high-voltage supply for CCE separation,the microchip with the coupled SLMEBE-CCE system was demonstrated by the pre-concentration,separation and detection of a mixed solution of fluorescein and butyl-rhodamine B.Compared to chip-based CCE without SLMEBE,the developed SLMEBE-CCE system produced a 7-fold increase in the signal of the model analyte of fluorescein and a 4-fold decrease in the signal of the model co-existing compound of butyl-rhodamine B.展开更多
建立了在线液相色谱-二极管阵列检测器-串联质谱技术(LC-DAD-MS/MS)同时测定野生菌中多肽类蘑菇毒素(鹅膏毒肽和鬼笔毒肽)的分析方法。样品经甲醇提取,水稀释后,在碱性条件下用XBridge^(TM) BEH C_(18)柱(150m m×3.0 m m,2.5μm)分...建立了在线液相色谱-二极管阵列检测器-串联质谱技术(LC-DAD-MS/MS)同时测定野生菌中多肽类蘑菇毒素(鹅膏毒肽和鬼笔毒肽)的分析方法。样品经甲醇提取,水稀释后,在碱性条件下用XBridge^(TM) BEH C_(18)柱(150m m×3.0 m m,2.5μm)分离,并先后用DAD和MS/MS检测。使用碱性流动相能够实现5种多肽类蘑菇毒素在15 m in内达到基线分离,同时又能有效抑制质谱加钠峰[M+Na]^+的响应信号,保证检测的稳定性和灵敏度。5种蘑菇毒素在0.05~500 mg/kg范围内线性关系良好,相关系数(r)>0.99;检出限为0.005~0.02 mg/kg。通过实际样品检测,证明该法操作简单、快速,灵敏度高,宽的定量检测线性范围能满足实际样品中蘑菇毒素含量变化大的特点。展开更多
In this work, two novel approaches were developed for miniaturized liquid-liquid(L-L) extraction on microfluidic chips, based on a stopped-flow extraction technique. In the first approach, trapped droplets extraction ...In this work, two novel approaches were developed for miniaturized liquid-liquid(L-L) extraction on microfluidic chips, based on a stopped-flow extraction technique. In the first approach, trapped droplets extraction mode, organic solvent droplets of a few hundred 10 -12 L were trapped within micro recesses fabricated in the channel walls of microfluidic chips, and analytes in aqueous streams flowing over the droplets were transferred into them, affecting a preconcentration. In the second approach, a stable interface between stationary organic phase and continuously flowed aqueous phase was formed by stopping the flow of organic phase. Analytes were transferred from the aqueous phase into the organic phase on the interface. Enrichment factors exceeding 1 000 and 300 were achieved with a preconcentration period of 20 min with sample consumption lower than 10 μL for trapped droplets and stopped-flow microextraction. In situ laser induced fluorescence detection of the concentrated analyte was performed following the preconcentration.展开更多
文摘This article presents the designing and fabrication of a microfluoidic chip with an integrated supported-liquid-membrane extraction-back-extraction and chip-based capillary electrophoresis system(SLMEBE-CCE).A 3-dimensional channel network for the SLMEBE-CCE system was fabricated with a four-layer glass/PTFE-membrane hybrid structure. With a gravity pump for sample and back-extraction solution delivery and a multi-channel high-voltage supply for CCE separation,the microchip with the coupled SLMEBE-CCE system was demonstrated by the pre-concentration,separation and detection of a mixed solution of fluorescein and butyl-rhodamine B.Compared to chip-based CCE without SLMEBE,the developed SLMEBE-CCE system produced a 7-fold increase in the signal of the model analyte of fluorescein and a 4-fold decrease in the signal of the model co-existing compound of butyl-rhodamine B.
文摘建立了在线液相色谱-二极管阵列检测器-串联质谱技术(LC-DAD-MS/MS)同时测定野生菌中多肽类蘑菇毒素(鹅膏毒肽和鬼笔毒肽)的分析方法。样品经甲醇提取,水稀释后,在碱性条件下用XBridge^(TM) BEH C_(18)柱(150m m×3.0 m m,2.5μm)分离,并先后用DAD和MS/MS检测。使用碱性流动相能够实现5种多肽类蘑菇毒素在15 m in内达到基线分离,同时又能有效抑制质谱加钠峰[M+Na]^+的响应信号,保证检测的稳定性和灵敏度。5种蘑菇毒素在0.05~500 mg/kg范围内线性关系良好,相关系数(r)>0.99;检出限为0.005~0.02 mg/kg。通过实际样品检测,证明该法操作简单、快速,灵敏度高,宽的定量检测线性范围能满足实际样品中蘑菇毒素含量变化大的特点。
文摘In this work, two novel approaches were developed for miniaturized liquid-liquid(L-L) extraction on microfluidic chips, based on a stopped-flow extraction technique. In the first approach, trapped droplets extraction mode, organic solvent droplets of a few hundred 10 -12 L were trapped within micro recesses fabricated in the channel walls of microfluidic chips, and analytes in aqueous streams flowing over the droplets were transferred into them, affecting a preconcentration. In the second approach, a stable interface between stationary organic phase and continuously flowed aqueous phase was formed by stopping the flow of organic phase. Analytes were transferred from the aqueous phase into the organic phase on the interface. Enrichment factors exceeding 1 000 and 300 were achieved with a preconcentration period of 20 min with sample consumption lower than 10 μL for trapped droplets and stopped-flow microextraction. In situ laser induced fluorescence detection of the concentrated analyte was performed following the preconcentration.
