Dissertation/Thesis Abstract

Lc-Ms Method Development for the Analysis of Antibiotics in Ddgs and Hormones in Blood
by Olendorff, Samantha, M.S., Southern Illinois University at Edwardsville, 2020, 86; 27736013
Abstract (Summary)

Antibiotics are used in the corn-to-ethanol process to control the proliferation of bacteria during fermentation. A by-product of fermentation is dried distiller’s grains with solubles (DDGS), which can be used as feed for cattle, turkeys, pigs, chicken, fish, and various other livestock. The antibiotics may still be present and active in the DDGS. Additionally, high amounts of antibiotic residues in the feed may lead to antibiotic resistant bacteria in humans and livestock. This study quantifies six different antibiotics using LCMS in a total of 78 samples from 33 different ethanol plants in 14 states. Antibiotics were extracted from DDGS samples by liquid-liquid extraction to remove the oil. The extract was then purified by solid phase extraction. The samples were tested by liquid chromatography-mass spectrometry in multiple reaction monitoring mode to quantify six antibiotics: penicillin G, erythromycin, tylosin, tetracycline, virginiamycin M, and virginiamycin S using the internal standards azithromycin-d3, penicillin G-d5, and ciprofloxacin-d8. DDGS was collected and analyzed quarterly over the course of twelve months to obtain a representation of DDGS produced in various parts of the US in different seasons. Penicillin G and tetracycline were each detected in a single sample. Tylosin was detected in 27%, erythromycin in 44%, virginiamycin M in 50%, and virginiamycin S in 82% of the total samples. Three or more antibiotics were detected in seven samples, while only a single sample had all six antibiotics detected.

The Female Athlete Triad can be present in athletic women. This phenomenon affects testosterone, estrogen, and other hormones, in addition to energy production and metabolism. It is theorized that this triad is also present in male athletes. Individuals from Southern Illinois University Edwardsville were analyzed for hormone analysis as well as energy expenditure and metabolism. Liquid-liquid extraction was performed on blood serum, and total testosterone (TT) was quantified by LCMS, while other analyses were performed by the Department of Exercise Physiology. It was determined that a majority of individuals had normal levels of testosterone, yet unusually high levels of estrogen.

The gender of a rat is determined by the production of testosterone in the brain. Testosterone can either be metabolized into 17β-Estradiol (E2) or dihydrotestosterone (DHT). Aromasin is a drug that blocks the production of E2, while Flutamide blocks the production of DHT. Rats were dosed with either Aromasin or Flutamide, and blood samples were analyzed for the quantification of TT by LCMS, as well as E2 by Exercise Physiology. The rats that were given Aromasin had higher levels of TT, and the rats given Flutamide had higher levels of E2.

Indexing (document details)
Advisor: Tucker, Kevin R.
Commitee: Zhang, Yanhong, Voss, Eric J., Dixon, Robert P.
School: Southern Illinois University at Edwardsville
Department: Chemistry
School Location: United States -- Illinois
Source: MAI 81/11(E), Masters Abstracts International
Source Type: DISSERTATION
Subjects: Chemistry
Keywords: Antibiotics, Blood, DDGS, LCMS, Testosterone
Publication Number: 27736013
ISBN: 9798645423315
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