Demonstration of direct bioanalysis of drugs in plasma using nanoelectrospray infusion from a silicon chip coupled with tandem mass spectrometry
Demonstration of direct bioanalysis of drugs in plasma using nanoelectrospray infusion from a silicon chip coupled with tandem mass spectrometry
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DOI：
10.1021/ac0260692
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发表时间：
2003-02-15
影响因子：
7.4
通讯作者：
Schultz, GA
中科院分区：
文献类型：
--
作者：
Dethy, JM;Ackermann, BL;Schultz, GA
通过直接纳米电喷雾输注耦合到串联质谱的定量生物分析已经实现了使用自动化液体采样器集成的微制造的电喷雾喷嘴的阵列，允许快速，连续的样品引入（1分钟/样品）。维拉帕米（r（2）= 0.999）及其代谢产物去甲维拉帕米（r（2）= 0.998）在2.5-500 ng/ mL范围内呈线性。根据观察到的精密度和准确度，将两种分析物的定量下限指定为5 ng/mL。样品制备包括用含有结构类似物galopamil作为内标的有机溶剂进行蛋白质沉淀。选择蛋白质沉淀以最大化通量并测试直接纳米电喷雾输注的稳健性。使用一次性导电移液管尖端将上清液的等分试样（10穆尔）转移到芯片的背面，用于以300 nL/min的流速直接输注。在芯片的前面，由通过移液管尖端施加到液体的电压引发。将芯片定位在三重四极质谱仪的API取样孔附近，所述三重四极质谱仪以选择的反应监测模式操作。结果表明，由于没有多余的液路，完全消除了系统携带污染，该技术通过减少方法开发和样品分析的时间，为药物发现中基于MS的筛选应用提供了潜在的优势。
Quantitative bioanalysis by direct nanoelectrospray infusion coupled to tandem mass spectrometry has been achieved using an automated liquid sampler integrated with an array of microfabricated electrospray nozzles allowing rapid, serial sample introduction (1 min/ sample). Standard curves prepared in human plasma for verapamil (r(2) = 0.999) and its metabolite norverapamil (r(2) = 0.998) were linear over a range of 2.5-500 ng/ mL. Based on the observed precision and accuracy, a lower limit of quantitation of 5 ng/mL was assigned for both analytes. Sample preparation consisted of protein precipitation with an organic solvent containing the structural analogue gallopamil as an internal standard. Protein precipitation was selected both to maximize throughput and to test the robustness of direct nanoelectrospray infusion. Aliquots of supernatant (10 muL) were transferred to the back plane of the chip using disposable, conductive pipet tips for direct infusion at a flow rate of 300 nL/min. Electrospray ionization occurred from the etched nozzles (30-mum o.d.) on the front of the chip, initiated by a voltage applied to the liquid through the pipet tip. The chip was positioned near the API sampling orifice of a triple quadrupole mass spectrometer, which was operated in selected reaction monitoring mode. Results are presented that document the complete elimination of system carry-over, attributed to lack of a redundant fluid path. This technology offers potential advantages for MS-based screening applications in drug discovery by reducing the time for methods development and sample analysis.