Characterization of a high-performance portable GC with a chemiresistor array detector.
Characterization of a high-performance portable GC with a chemiresistor array detector.
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DOI：
10.1039/b810944c
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发表时间：
2009-02
期刊：
影响因子：
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通讯作者：
Q. Zhong;W. H. Steinecker;E. Zellers
中科院分区：
文献类型：
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作者：
Q. Zhong;W. H. Steinecker;E. Zellers
描述了一种新型的第二代便携式气相色谱仪（GC）原型的实验室特性，该原型设计用于挥发性有机化合物（VOC）的复杂混合物的痕量测定。该仪器包括一个小型多级吸附剂预富集器/进样器（PCI），两个串联分离柱，具有快速、独立的温度编程能力和连接点压力/流量控制，以及一个由一系列微制造化学电阻（CR）传感器组成的检测器，该传感器涂有硫代酸单层保护金纳米颗粒薄膜。CR阵列的响应模式与色谱保留时间一起用于识别洗脱混合物成分。经洗涤的环境空气用作载气。与先前报道的第一代原型仪器相比，设计上的改进大大降低了检测极限，并提高了分辨率、可靠性、灵活性和便利性。介绍了该仪器的主要特性，重点介绍了在不同温度和流量下操作时传感器阵列性能的权衡。在不到7分钟的时间内分离了31种挥发性有机化合物的预浓缩混合物。假设样品体积为1l，大多数化合物的预计检出限在ppt范围内。
The laboratory characterization of a novel, second-generation portable gas chromatograph (GC) prototype designed for trace-level determinations of complex mixtures of volatile organic compounds (VOC) is described. The instrument incorporates a small, multi-stage adsorbent preconcentrator/injector (PCI), two series-coupled separation columns with fast, independent temperature-programming capabilities and junction-point pressure/flow control, and a detector consisting of an array of microfabricated chemiresistor (CR) sensors coated with thiolate-monolayer-protected gold nanoparticle films. Response patterns from the CR array are used in conjunction with chromatographic retention times to identify eluting mixture components. Scrubbed ambient air is used as the carrier gas. Enhancements in design relative to a previously reported first-generation prototype instrument have led to significant reductions in limits of detection as well as improvements in resolution, reliability, flexibility, and convenience. Key features of the instrument are characterized, with an emphasis on the tradeoffs in sensor array performance associated with operation at different temperatures and flow rates. The separation of a preconcentrated mixture of 31 VOCs in < 7 minutes is demonstrated. Projected detection limits are in the ppt range for most compounds, assuming a 1 L sample volume.