Date on Master's Thesis/Doctoral Dissertation
8-2024
Document Type
Master's Thesis
Degree Name
M. Eng.
Department
Chemical Engineering
Degree Program
JB Speed School of Engineering
Committee Chair
Fu, Xiao-An
Committee Member
Willing, Gerold
Committee Member
Berson, Eric
Committee Member
Sumanasekera, Gamini
Author's Keywords
SiO2; orthoxylene; metaxylene; preconcentration; CAR/PDMS, chemiresistors
Abstract
Volatile Organic Compounds (VOCs) are a class of toxic chemicals in environmental air associated with several serious health risks. Some of the most common and concerning VOCs are Benzene, Toluene, Ethyl Benzene, and Xylene (BTEX). To maintain healthy air quality in these environments, researchers pursue instruments and processes to quickly and accurately predict sub-ppb concentrations of BTEX in indoor and outdoor air. By employing a micropreconcentrator (μPC) to combine Solid-Phase Micro-Extraction (SPME) with Gas Chromatography Mass Spectrometry (GC-MS) analysis, trace BTEX content in air samples can be captured, extracted and analyzed. In this thesis, a dual-compartment μPC with Carboxen 1000 as an adsorbent, and silica gel in the second compartment, was used to analyze environmental air samples from across the University of Louisville Belknap Campus for BTEX, using a combination of SPME, thermal desorption, and GC-MS. Using standard samples of BTEX concentrated in synthetic air, a calibration curve was designed. Concentrations of BTEX including 20 ppb, 40 ppb, 100 ppb, and 200 ppb were analyzed using SPME and GC-MS, without the use of a preconcentrator, to construct a calibration curve to measure BTEX content in environmental and standard air. Then a single-compartment Carboxen μPC was used to analyze prepared samples of BTEX in synthetic air, at concentrations of 1 and 5 ppb. Considering the volume compression of air processed by the μPC, data from these samples were directly compared to those corresponding to 20-ppb and 100-ppb standard samples, to assess the percent recovery of BTEX across micropreconcentration.
Recommended Citation
Spargo, Raymond Daniel, "Carboxen Micropreconcentrator performance for analyzing BTEX in air." (2024). Electronic Theses and Dissertations. Paper 4410.
Retrieved from https://ir.library.louisville.edu/etd/4410
