Facile Hyphenation of Gas Chromatography and a Microcantilever Array Sensor for Enhanced Selectivity
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- 作者：Peter J. Chapman ; Frank Vogt ; Pampa Dutta ; Panos G. Datskos ; Gerald L. Devault ; Michael J. Sepaniak
- 刊名：Analytical Chemistry
- 出版年：2007
- 出版时间：January 1, 2007
- 年：2007
- 卷：79
- 期：1
- 页码：364 - 370
- 全文大小：266K
- 年卷期：v.79,no.1(January 1, 2007)
- ISSN：1520-6882
文摘
The very simple coupling of a standard, packed-columngas chromatograph with a microcantilever array (MCA)is demonstrated for enhanced selectivity and potentialanalyte identification in the analysis of volatile organiccompounds (VOCs). The cantilevers in MCAs are differentially coated on one side with responsive phases (RPs)and produce bending responses of the cantilevers due toanalyte-induced surface stresses. Generally, individualcomponents are difficult to elucidate when introduced toMCA systems as mixtures, although pattern recognitiontechniques are helpful in identifying single components,binary mixtures, or composite responses of distinctmixtures (e.g., fragrances). In the present work, simpletest VOC mixtures composed of acetone, ethanol, andtrichloroethylene (TCE) in pentane and methanol andacetonitrile in pentane are first separated using a standardgas chromatograph and then introduced into a MCA flowcell. Significant amounts of response diversity to theanalytes in the mixtures are demonstrated across the RP-coated cantilevers of the array. Principal componentanalysis is used to demonstrate that only three components of a four-component VOC mixture could be identified without mixture separation. Calibration studies areperformed, demonstrating a good linear response over 2orders of magnitude for each component in the primarystudy mixture. Studies of operational parameters including column temperature, column flow rate, and array celltemperature are conducted. Reproducibility studies ofVOC peak areas and peak heights are also carried outshowing RSDs of less than 4 and 3%, respectively, forintra-assay studies. Of practical significance is the facilemanner by which the hyphenation of a mature separationtechnique and the burgeoning sensing approach is accomplished, and the potential to use pattern recognitiontechniques with MCAs as a new type of detector forchromatography with analyte-identifying capabilities.