| As pharmaceutical usage is increasing, they are becoming increasingly ubiquitous in the environment. The synergistic effects associated with chronic exposure is still being realized, but certain pharmaceutical classes are closely associated with increase of antibiotic resistant genes (ARGs) and adverse psychological effects in aquatic organisms. Consequently, it is critical to understand the levels being released as a result of current practices and to be proactive in anticipating and investigating new routes of exposure. The research presented here investigates pharmaceutical fate from both regulatory and exploratory sources, including conventional full-scale and advanced pilot-scale wastewater treatment processes, and common and novel fertilizing techniques by liquid chromatography tandem mass spectrometry (LC-MS/MS). Sample extraction and instrument methods were developed, optimized, and validated. Conventional and advanced wastewater treatment plant (WWTP) stages across 5 WWTPs were investigated for removal efficiency of pharmaceuticals, and a deeper look was taken at an advanced ozonation WWTP process in order to identify transformation products of antidepressants. Next, the fate of pharmaceuticals in human urine when it was processed and applied as an agricultural fertilizer was investigated. Lastly, young maize plants were grown in manure-amended soil and plant uptake and occurrence of ARGs was explored.;Chapter 2 investigates a popular precursor m/z used for the demethylated metabolite of the antidepressant sertraline, norsertraline. The base peak of nosertraline is an in-source fragment shared by sertraline and D3-sertraline, and without chromatographically resolving sertraline from norsertraline, the signals interfere. This study demonstrates the importance of determining the structure of the precursor ion and testing for interferences when adding new compounds to instrument methods.;A targeted LC-MS/MS method evaluated the removal efficiency of pharmaceuticals by the secondary and tertiary stages of treatment within 5 WWTPs are compared in Chapter 3. Conventional activated sludge was effective at removing acetaminophen and caffeine, but not antibiotics or antidepressants. An activated carbon filter was effective at removing all pharmaceuticals except sulfamethoxazole, with a total average of 95% removal, whereas a moving bed biofilm reactor was ineffective at removing pharmaceuticals with an average of --3% removal. Ozonation had an average removal of 80% and was found to be effective at removing pharmaceuticals, with the exception of fluoxetine which was only detected in that WWTP.;Sample extraction methods in matrices associated with human urine fertilization were optimized in Chapter 4. The goal of this study was to develop sensitive methods for the analysis of pharmaceuticals in urine, struvite, lysimeter water, soil, and food crops using liquid chromatography with tandem mass spectrometry (LC-MS/MS). The ability to detect low levels of pharmaceutical residues in various environmental matrices will aid in assessing the potential risks associated with the field application of urine that is used to fertilize croplands. The optimized method reported in this paper, which utilizes solid phase extraction for sample clean-up and pre-concentration, offers analyte recoveries ranging from 29 to 112 percent, and detection limits ranging from 0.89 ng L --1 to 0.0047 microg g--1.;Human urine is an abundant, renewable resource that can be used as a valuable source of fertilizer because it is rich in nitrogen, phosphorus and potassium. As fertilizers derived from urine become more widely used, it is important to understand how excreted pharmaceuticals are transported from urine to the environment. Many pharmaceuticals are excreted from the human body in their native form; therefore, when urine is used as a fertilizer, biologically active pharmaceuticals can be released into the environment. The goal of Chapter 5 was to utilize methods developed in Chapter 4 to analyze human urine, struvite, lysimeter water, soil and food crops to understand the uptake of pharmaceuticals in a field study. Struvite precipitated from urine had at least 5x less pharmaceuticals than the urine. Since the amount of struvite or urine applied is dependent on the concentration of phosphorous or nitrogen, pharmaceuticals in food crops were normalized to the mass of fertilizer applied.;In Chapter 6, Zea mays seeds were planted under three different conditions: dairy manure-amended soil, antibiotic spiked dairy manure-amended soil, and untreated soil, in order to explore the potential plant uptake of antimicrobials and the prevalence of antibiotic resistant genes (ARGs) present in manure. The antibiotic spiked manure was fortified with an additional 1 ppm of sixteen antimicrobials belonging to sulfonamides and tetracyclines classes, in order to understand their fate and whether they had an impact on ARGs. The Zea mays was harvested after three weeks to determine the uptake of antibiotics, and whether ARG transfer from soil to plant had occurred. Antimicrobial analysis was done using liquid chromatography tandem mass spectrometry (LC-MS/MS) and ARGs: sul1, tetO, and OXA-1 were analyzed using Real-Time quantitative Polymerase Chain Reaction (RT qPCR). (Abstract shortened by ProQuest.). |
