AVS 64th International Symposium & Exhibition
    Actinides and Rare Earths Focus Topic Tuesday Sessions
       Session AC-TuP

Paper AC-TuP2
Sputter-Deposited Layers for Solid Phase Microextraction

Tuesday, October 31, 2017, 6:30 pm, Room Central Hall

Session: Actinide and Rare Earth Poster Session
Presenter: Tuhin Roychowdhury, Brigham Young University
Authors: T. Roychowdhury, Brigham Young University
D. Patel, Brigham Young University
M.R. Linford, Brigham Young University
Correspondent: Click to Email
Solid phase microextraction (SPME) is an effective analyte sampling method. It works by placing a coated fiber above a sample (headspace mode) or immersing it in a liquid sample such that molecules (analytes) of interest can be selectively captured and concentrated. The extracted species are then released into a chromatograph for separation, identification, and quantification. It is a ‘green’ method as no additional solvent is required in this process. Recently, we have developed a new class of SPME fibers that offer extraordinary capacity, sensitivity, and speed. They are prepared by sputtering a material under conditions that lead to a robust nanoporous coating on the fiber. In particular, silicon sputtering generates a porous surface that can be additionally oxidized, leading to a high density of silanol groups than can be subsequently silanized or used in other depositions. The surfaces and materials generated for SPME in this project have been characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), spectroscopic ellipsometry (SE), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and wetting. They confirm the synthesis of highly porous, hydrophobic materials. The performance of our 2 micron sputtered coatings has been compared to that of thicker (7 micron) commercial coating. Our fiber consistently outperforms the commercial fiber, showing significantly higher capacity, for example, for high molecular weight polycyclic aromatic hydrocarbons (PAHs). PAHs are a significant environmental pollutant. (They are produced from industrial wastes, incomplete combustion of fossil fuels, and natural emissions, and are detrimental to human health and the environment due to their carcinogenicity.) Hence, there is a need to identify these toxic pollutants. Real world samples, e.g., hops have also been analyzed. Different sputter coating thicknesses have been prepared and evaluated.