Department of Chemistry, National Taiwan Normal University, 88 Sec. 4, Tingchow Road, Taipei, Taiwan.
Anal Chem. 2010 Sep 1;82(17):7467-71. doi: 10.1021/ac101675z.
A simple milli-whistle was developed for the use in GC (gas chromatography) detection, in which, compared to a thermal conductivity detector (TCD), 1 order of magnitude superior sensitivity can be obtained. The milli-whistle can be connected to the outlet of a GC capillary. The gas and makeup gas passing through the capillary produces a sound as it passes through the milli-whistle (i.e., the gas of the GC eluate). The sound can easily be detected by a microphone, which, after a Fourier transform (FT) by means of a LabVIEW (Laboratory Virtual Instrumentation Engineering Workbench) built-in program, a very sharp frequency peak (full width at half-maximum, approximately 1.6 Hz) can be simultaneously observed. As a result, GC elutes can be qualitatively determined on the basis of their retention times, and a quantitative analysis can be achieved on the basis of the frequency shifts. When the makeup and carrier gases used were nitrogen, in the case of gas samples, including hydrogen, helium, argon, and carbon dioxide, the limits of detection were found to be approximately 3 microL/each injection; in the case of liquid samples, including methanol, cyclohexane, tetrahydrofuran, hexane, and acetone, the limits of detection were determined to be approximately 10 microg/each injection, respectively. When the gases were changed to hydrogen, the limits of detection were dramatically improved. When acetone was selected as the model sample, a linear relationship was found in the range of 0.2-200 microg/injection.
一种简单的毫微微音器被开发用于 GC（气相色谱）检测，与热导检测器（TCD）相比，它可以获得高一个数量级的灵敏度。毫微微音器可以连接到 GC 毛细管的出口。当气体和载气通过毛细管时，会产生声音，因为它通过毫微微音器（即 GC 洗脱物的气体）。声音可以很容易地被麦克风检测到，通过使用内置的 LabVIEW（实验室虚拟仪器工程工作台）程序进行傅里叶变换（FT），可以同时观察到一个非常尖锐的频率峰（半最大值全宽，约为 1.6 Hz）。因此，可以根据保留时间对 GC 洗脱物进行定性分析，并根据频率偏移进行定量分析。当使用的载气和辅助气为氮气时，对于包括氢气、氦气、氩气和二氧化碳在内的气体样品，检测限约为每个进样 3 μL；对于包括甲醇、环己烷、四氢呋喃、己烷和丙酮在内的液体样品，检测限分别约为每个进样 10 μg。当气体改为氢气时，检测限显著提高。当选择丙酮作为模型样品时，在 0.2-200 μg/进样范围内发现了线性关系。
