Multiplexed detection of nitrate and nitrite for capillary electrophoresis with an automated device for high injection efficiency.
Multiplexed detection of nitrate and nitrite for capillary electrophoresis with an automated device for high injection efficiency.
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DOI：
10.1039/b510156e
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发表时间：
2006-01
期刊：
影响因子：
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通讯作者：
Leyi Gao;Eric E. Patterson;S. Shippy
中科院分区：
文献类型：
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作者：
Leyi Gao;Eric E. Patterson;S. Shippy
一种简单的自动化纳升级注射装置，可从体积 <1 µL 的样品中重复注射 5 nL 样品，已成功用于传统毛细管电泳 (CE) 和 Hadamard 变换 (HT) CE 检测。两个标准熔融石英毛细管通过设备轴向组装，用作注射毛细管和分离毛细管。使用电磁阀控制的压力将样品溶液供应到注射毛细管。缓冲溶液通过注射毛细管和分离毛细管的连接处以重力方式流动，并且也通过电磁阀进行控制。将样品塞推入注射毛细管和分离毛细管之间的空间以进行电动注射。为了评估注射装置的性能，进行了多项优化，包括流速、注射样品体积和缓冲液横流控制对整体灵敏度的影响。然后将该系统应用于 HT-CE-UV 检测，以提高一氧化氮 (NO) 代谢物、亚硝酸盐和硝酸盐的信噪比 (S/N)。此外，还进行了信号平均，以探索与单次进样相比更大灵敏度增强的可能性。
A simple automated nanoliter scale injection device which allows for reproducible 5 nL sample injections from samples with a volume of <1 microL is successfully used for conventional capillary electrophoresis (CE) and Hadamard transform (HT) CE detection. Two standard fused silica capillaries are assembled axially through the device to function as an injection and a separation capillary. Sample solution is supplied to the injection capillary using pressure controlled with a solenoid valve. Buffer solution flows gravimetrically by the junction of the injection and separation capillaries and is also gated with a solenoid valve. Plugs of sample are pushed into the space between the injection and separation capillaries for electrokinectic injection. To evaluate the performance of the injection device, several optimizations are performed including the influence of flow rates, the injected sample volume and the control of the buffer transverse flow on the overall sensitivity. The system was then applied to HT-CE-UV detection for the signal-to-noise ratio (S/N) improvement of the nitric oxide (NO) metabolites, nitrite and nitrate. In addition, signal averaging was performed to explore the possibility of greater sensitivity enhancements compared to single injections.