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Nanomaterials For Liquid Chromatography and Laser Desorption/Ionization Mass Spectrometry

Lu, Tian
http://rave.ohiolink.edu/etdc/view?acc_num=osu1376981440

Abstract Details

2013, Doctor of Philosophy, Ohio State University, Chemistry.
Techniques in analytical chemistry have been greatly improved by the application of developing nanotechnology. Separation science and mass spectrometry are two of the most widely-used techniques in industry. The enhanced performance of liquid chromatography (LC), solid phase extraction (SPE), laser desorption/ionization mass spectrometry was achieved here by using novel nanotechnology and nanomaterials. Electrospun polyvinyl alcohol (PVA) ultrathin layer chromatographic (UTLC) plates were fabricated using in-situ crosslinking electrospinning technique. The value of these ULTC plates was characterized using the separation of fluorescein isothiocyanate (FITC) labeled amino acids and the separation of amino acids followed visualization using ninhydrin. Carbon has been used widely in HPLC due to its unique selectivity and high stability. Currently commercially-available carbon stationary phases are amorphous carbon. Amorphous carbon as a stationary phase has at least two sites of interaction with analytes: basal-plane and edge-plane carbon sites. The polarity and adsorption property of the two sites are different. However, the composition of the two sites cannot be controlled and predicted. Moreover, there may be different functional groups attached on edge-plane sites. In this work, homogenous carbon stationary phase is prepared by surface-directed liquid crystal assembly. By controlling the polarity of the substrates homogenous edge-plane or basal-plane carbon can be synthesized. To evaluate the performance of homogeneous carbon stationary phase, linear solvation energy relationships were used to compare these ordered carbon surfaces to commercially-available carbon stationary phases. Reversed-phase separations of nucleosides and nucleotides, and amino acids were demonstrated using the ordered carbon surfaces. Homogeneous basal-plane carbon nanorods were also prepared for SPE. The homogenous basal-plane carbon nanorods were prepared with silver coated anodic aluminum oxide membrane template method. Benzene, ethylbenzene, phenol and pcresol were used as analytes. The preliminary SPE results showed that the basal-plane carbon has higher extraction efficiency to the hydrophobic analytes, benzene and ethylbenzene and lower extraction efficiency to the polar analytes, phenol and p-cresol. The results further demonstrate that the basal-plane carbon surface is more hydrophobic and enhanced selectivity can be achieved by using homogenous carbon with different carbon alignment. Electrospun polymer nanofibers (polyacrylonitrile, polyvinyl alcohol, and SU-8 photoresist), and carbon nanofibers pyrolyzed to final temperatures of 600, 800 and 900 degrees Celsius were used as substrates for surface-assisted laser desorption/ionization (SALDI) and matrix-enhanced surface-assisted laser desorption/ionization (ME-SALDI) analyses. Polyethylene glycol with a molecular weight as high as 900,000 Da was successfully detected using the carbon nanofibrous substrate processed to 800 degrees Celsius. High quality polystyrene mass spectra were obtained for the first time using SALDI nanofibrous polyacrylonitrile substrates. The results from ME-SALDI showed enhanced signal to noise ratios for the analytes with the electrospun nanofibrous substrates compared to using a conventional stainless steel substrate. A detection limit of 400 amol was achieved for angiotensin I using the carbon nanofibrous ME-SALDI substrate. In addition, the modified carbon particles with photoluminescence were prepared. A fluorophore was attached to the carbon surface. Because carbon is a strong fluorescent quencher, a spacer containing a long carbon chain was used to minimize the quenching from carbon.
Susan Olesik (Advisor)
Terry Gustafson (Committee Member)
Philip Grandinetti (Committee Member)
Lee Potter (Committee Member)
296 p.
Chemistry

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Citations

  • Lu, T. (2013). Nanomaterials For Liquid Chromatography and Laser Desorption/Ionization Mass Spectrometry [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1376981440

    APA Style (7th edition)

  • Lu, Tian. Nanomaterials For Liquid Chromatography and Laser Desorption/Ionization Mass Spectrometry. 2013. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1376981440.

    MLA Style (8th edition)

  • Lu, Tian. "Nanomaterials For Liquid Chromatography and Laser Desorption/Ionization Mass Spectrometry." Doctoral dissertation, Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1376981440

    Chicago Manual of Style (17th edition)

osu1376981440
236
© 2013, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.