Phoebe Zito

University of New Orleans | UNO · Department of Chemistry

The presence of nanomaterials, whether designed for photochemistry or not, can have dramatic impacts on environmental, plant, and animal systems. In order to fully utilize nanomaterials for photochemical and other applications, it is necessary to design and manage them in a way that avoids undesirable or unexpected consequences. To provide a solid...

Despite the fact that oil chemistry and oil spills have been studied for many years, there are still emerging techniques and unknown processes to be explored. The 2010 Deepwater Horizon oil spill in theGulf of Mexico resulted in a revival of oil spill research across a wide range of fields. These studies provided many new insights, but unanswered q...

Elevated non-volatile dissolved organic carbon (NVDOC) concentrations in groundwater (GW) monitoring wells under oil-contaminated hydrophobic soils originating from a pipeline rupture at the National Crude Oil Spill & Natural Attenuation Research Site near Bemidji, MN are documented. We hypothesized the elevated NVDOC is comprised of water-soluble...

The short-and long-term impacts of nanoparticles (NPs) in consumer products are not fully understood. Current European Union (EU) regulations enforce transparency on products containing NPs in cosmetic formulations; however, those set by the U.S. Food and Drug Administration are lacking. This study demonstrates the potential of single-particle indu...

Oil spills are devastating to seabirds causing high levels of mortality and toxic physiological effects, especially to immune function. Sunlight exposure can further enhance the toxicity of oil to marine species by generating photodegradation products. Photo-enhanced oil toxicity to marine birds has not been studied. Therefore, the goal of this pro...

Previous laboratory studies developed a conceptual model based on elevated non-volatile dissolved organic carbon (NVDOC) concentrations after photodegradation and subsequent dissolution of Macondo oil following the Deepwater Horizon blowout. However, those experiments did not account for the effects of ~1 million gallons of dispersant applied to th...

Rare earth elements (REEs) make up a group of unique elements with diverse applications in energy, medicine, and technology. Increasing global demand and limited supplies have led to exploring the economic viability of domestic feedstock extraction from sources such as coal. Little is known about the release of REEs from coal due to the environment...

Photo-oxidized petroleum hydrocarbons are a unique class of water-soluble bioavailable compounds that have gained emerging recognition within toxic regulatory management bodies as an urgent and priority research need in high latitudes. In order to characterize the molecular signatures of photo-oxidized petroleum, bench-scale spills were irradiated...

Chemical herders and in-situ burning (ISB) are designed to mitigate the effects that oil spills may have on the high latitude marine environment. Little information exists on the water solubilization of petroleum residues stemming from chemically herded ISB and whether these bioavailable compounds have measurable impacts on marine biota. In this ex...

Oil is a complex mixture of alkanes, cycloalkanes, aromatics, nitrogen/sulfur/oxygen (N/S/O) heterocycles, alcohols, ketones, carboxylic acids, porphyrins, and myriad possible combinations therein. Once introduced into the environment, some weathering processes reduce this complexity through evaporative losses (loss to atmosphere) as well as water...

Petroleum derived dissolved organic matter (DOMHC) samples were successfully cationized with barium, revealing many [M-H+Ba]+ peaks in both dark and simulated sunlight treatments. The DOMHC samples generated after light exposure exhibited a greater number of [M-H+Ba]+ peaks compared to the dark control. Multiple [M-H+Ba]+ peaks were investigated in...

Relationships between dissolved organic matter (DOM) reactivity and chemical composition in a groundwater plume containing petroleum-derived DOM were examined by quantitative and qualitative measurements to determine the source and chemical composition of the compounds that persist downgradient. Samples were collected from a transect down the core...

Permafrost is an extreme habitat yet it hosts microbial populations that remain active over millennia. Using permafrost collected from a Pleistocene chronosequence (19 to 33 ka), we hypothesized that the functional genetic potential of microbial communities in permafrost would reflect microbial strategies to metabolize permafrost soluble organic ma...

High‐resolution mass spectrometry (HRMS) has become a vital tool for dissolved organic matter (DOM) characterization. The upward trend in HRMS analysis of DOM presents challenges in data comparison and interpretation among laboratories operating instruments with differing performance and user operating conditions. It is therefore essential that the...

The Central Siberian Plateau is undergoing rapid climate change that has resulted in increased frequency of forest fires and subsequent alteration of watershed carbon and nutrient dynamics. Across a watershed chronosequence (3 to >100 years since wildfire) we quantified the effects of fire on quantity and composition of dissolved organic matter (DO...

Spilled oil is highly susceptible to sunlight induced transformations, both as films on the surface of water as well as material dissolved or dispersed in the water column. We utilized ultrahigh-resolution mass spectrometry and optical spectroscopy to understand shifts in oil photoproduct distribution as a function of photooxygenation. Oxygenation...

Understanding the entirety of basin-scale C cycling (DOC fluxes and CO 2 exchanges) are central to a holistic perspective of boreal forest biogeochemistry today. Shifts in the timing and magnitude of dissolved organic carbon (DOC) delivery in streams and eventually into oceans can be expected, while simultaneously CO 2 emission may exceed CO 2 fixa...

The extraction efficiency of petroleum‐derived dissolved organic matter (DOM) was examined for groundwater samples from an aquifer contaminated with crude oil. Five different types of extraction techniques were investigated to determine which method is best suited for the analysis of potentially toxic petroleum‐derived DOM. The five types were a li...

Permafrost thaw subjects previously frozen organic carbon (OC) to microbial decomposition, generating the greenhouse gases (GHG) carbon dioxide (CO2) and methane (CH4) and fueling a positive climate feedback. Over one‐quarter of permafrost OC is stored in deep, ice‐rich Pleistocene‐aged yedoma permafrost deposits. We used a combination of anaerobic...

In order to examine the molecular-level composition and acute toxicity of petroleum-derived dissolved organic matter (DOMHC) produced via photo-oxidation, a heavy and light oil were irradiated over seawater with simulated sunlight. Increases in dissolved organic carbon (DOC) concentrations as a function of time were associated with changes in DOMHC...

The Qinghai–Tibet Plateau (QTP) accounts for approximately 70 % of global alpine permafrost and is an area sensitive to climate change. The thawing and mobilization of ice-rich and organic-carbon-rich permafrost impact hydrologic conditions and biogeochemical processes on the QTP. Despite numerous studies of Arctic permafrost, there are no reports...

Mountain glaciers store dissolved organic carbon (DOC) that can be exported to river networks and subsequently respired to CO2. Despite this potential importance within the global carbon cycle, the seasonal variability and downstream transport of glacier-derived DOC in mountainous river basins remains largely unknown. To provide novel insight, here...

Rivers deliver approximately 260 Tg of dissolved organic carbon (DOC) to the ocean annually, yet there is little evidence of terrigenous DOC (tDOC) in the ocean. While tDOC was historically believed to be stable and resistant to microbial degradation, it has recently been shown that freshwater systems mineralize more tDOC than originally thought. T...

An efficient method for the construction of the 5-fluoro-4-hydroxypentyl side chain common to a number of synthetic cannabinoid metabolites was developed. A series of hydroxyl protecting groups was examined to assess the viability as orthogonal protecting groups for epoxidation and regioselective hydrofluorination. The 1-[5-fluoro-4-(diphenyl-tert-...

The Qinghai-Tibetan Plateau (QTP) accounts for approximately 70 % of global alpine permafrost and is an area sensitive to climate change. The thawing and mobilization of ice and organic carbon-rich permafrost impact hydrologic conditions and biogeochemical processes on the QTP. Despite numerous studies of Arctic permafrost, there are no reports to...

Groundwater samples containing petroleum-derived dissolved organic matter (DOMHC) originating from the north oil body within the National Crude Oil Spill Fate and Natural Attenuation Research Site near Bemidji, MN, USA were analyzed by optical spectroscopic techniques (i.e., absorbance and fluorescence) to assess relationships that can be used to e...

Ongoing global temperature rise has caused significant thaw and degradation of permafrost soils on the Qinghai-Tibetan Plateau (QTP). Leaching of organic matter from permafrost soils to aquatic systems is highly complex and difficult to reproduce in a laboratory setting. We collected samples from natural seeps of active and permafrost layers in an...

Significance Atmospheric N deposition affects productivity and biodiversity of forests worldwide. However, field-based estimates of atmospheric N deposition for tropical forests are extremely sparse. Our results from a monitoring network in the central Congo Basin exceed current regional N deposition simulations. Ultrahigh-resolution mass spectrome...

While the biogeochemical forces influencing the weathering of spilled oil have been investigated for decades, the environmental fate and effects of ‘oxyhydrocarbons’ in sand patties deposited on beaches are not well known. We collected sand patties deposited in the swash zone on Gulf of Mexico beaches following the Deepwater Horizon oil spill. When...

The acidic components of Athabasca bitumen interfacial material (IM) were isolated and subsequently fractionated based on hydrophobicity by a modified aminopropyl silica (MAPS) method to determine whether low-molecular-weight IM acids are preferentially ionized in negative-ion electrospray ionization (ESI (−)) and, thus, bias the compositional info...

Crude oil is a complex mixture of many thousands of mostly hydrocarbon and nitrogen-, sulfur-, and oxygen-containing compounds with molecular weights ranging from below 70 Da to well over 2,000 Da. When this complex mixture enters the environment from spills, ruptures, blowouts, or seeps, it undergoes a continuous series of compositional changes th...

Adsorption is widely popular for removal of heavy metals due to its low cost, efficiency, and simplicity. The focus of this review will be the use of inorganic adsorbents engineered at the nanoscale. The applicability of iron oxide (hematite, magnetite and maghemite), carbon nanotubes (CNT), and metal oxide based (Ti, Mn, Zn) and polymeric nano ads...

Photochemical production of organic triplets from six different petroleum samples was measured through the cis-trans isomerization of 1,3-pentadiene in Gulf water. The data correlate very well with previously measured singlet oxygen generation rates. Triplet state energies in solar irradiated oil were measured in the range of 280-300 kJ/mol. The ph...

Photochemical production of singlet oxygen from thin oil films over seawater and pure water was measured with furfuryl alcohol as a selective chemical probe. Oil was collected from the surface of the Gulf of Mexico following the Deepwater Horizon spill and from other sources. The loss of furfuryl alcohol and the formation of 6-hydroxy(2H)pyran-3(6H...

Oil spilled in aquatic systems is exposed to sunlight, resulting in important photochemical processes. Photochemistry likely plays a major role in the fate of oil spilled in areas with sunlight exposure, especially since high molecular weight aromatics are readily photodegraded but are resistant to biodegradation. In order to gain a clearer underst...

Sunlight exposed oil films on seawater or pure water produced substantial amounts of hydroxyl radical as a result of irradiation. Oil was collected from the surface of the Gulf of Mexico following the Deepwater Horizon spill and exposed to simulated sunlight in thin films over water. Photochemical production of hydroxyl radical was measured with be...

The photochemical behavior of Deepwater Horizon oil collected from the surface of the Gulf of Mexico was studied. Thin oil films on water were subjected to simulated sunlight, and the resulting chemical and optical changes were observed. Polycyclic aromatic hydrocarbons (PAHs) showed substantial photodegradation, with larger PAHs being more rapidly...

Photochemical production of hydroxyl radical from thin oil films over seawater and pure water was measured with benzoic acid as a selective chemical probe. Oil was collected from the surface of the Gulf of Mexico following the Deepwater Horizon spill. Benzoic acid reacts with hydroxyl radical to form hydroxybenzoic acids, with p-hydroxybenzoic acid...