作者: Stanley D. Stearns , Huamin Cai , J. Art Koehn , Martin Brisbin , Chris Cowles
DOI: 10.1016/J.CHROMA.2010.04.050
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摘要: Nickel clad or nickel wired fused silica column bundles were constructed and evaluated. The sheathing wire functions not only as the heating element for direct resistive heat, but also temperature sensor, since has a large coefficient. With this method controller is able to apply power measure simultaneously on same element, which can effectively avoid overshoot caused by any delayed response of sensor element. This approach eliminates cool spot where separate touches column. There are some other advantages bundle structure: (1) be heated quickly because column's low mass, shortening analysis time. We demonstrate maximum rate 13 degrees C/s (800 C/min). (2) Cooling time short, increasing sample throughput. drops from 360 C 40 less than 1 min. (3) Power consumption very - 1.7 W/m (8.5 W total) 5 m 0.69 (10.4 15 when they kept at 200 isothermally. programming, then 70 an 800 C/min ramp 350 C. (4) small, with diameter about 2.25 in. All these make ideal fast GC portable instruments. Column efficiencies retention repeatability have been evaluated compared conventional oven in study. For isothermal conditions, measured effective theoretical plate number. It was found that number heat always due uneven bundle. However, loss significant average 1.5% 4.5% Separation numbers used comparison results similar those observed conditions. Retention 0.010% RSD isotheral 0.037% obtained heat. Applications demonstrated, including diesel PAH analysis.