Dr. Pamela P Benz

Petroleum products are introduced into the environment through a variety of mechanisms and are shown to produce highly reactive oxygen species though photochemical reactions. For example, potential contamination can occur from motor oil leaked or spilled by recreational water vehicles such as boats and jet skis. Motor oils, both synthetic and non-synthetic, can produce potentially toxic components through natural weathering processes. Chemicals produced through photochemical processes are examined to help assess overall ecosystem impact and better understand mechanisms of toxicity. This study examined photochemical degradation and subsequent toxicity of both crude oil and water collected from local marinas. Using a high performance liquid chromatography (HPLC) method for detection of hydroxyl radical (·OH ), benzoic acid was added to each sample prior to irradiation. Benzoic acid served as a radical trap for OH produced. The resulting formation of para-hydroxybenzoic acid (p-HBA) was measured and total ·OH formation determined.

This qualitative case study presents interview responses, classroom observations, and survey responses of college students in an introductory chemistry course. The participants engaged in required, weekly sessions that were focused on facilitating active learning. The data were framed through a community of practice theoretical framework and emergent themes were centered on the following components: mutual engagement, joint enterprise, and shared repertoire. Participants’ engagement led to collaborations beyond the required, weekly sessions that included forming study groups and seeing chemistry tutors. They also shared study techniques that were based on the mutual understanding that chemistry learning required routine practice. Implications for college leaders and researchers about implementing research-based pedagogies are discussed.

Various petroleum products leak into the environment through different mechanisms, and may include crude oil or refined motor oil. These compounds and their accompanying weathered by-products can be damaging to the environment. To help assess the impact of weathered petroleum products on the environment. this study investigates the formation of reactive oxygen species, such as hydroxy radical. Water accommodated fractions (WAFs) are samples of water mixed with either crude or moto, on and are used to mimic environmental conditions. Over time water soluble components of the oil separate into the water layer of the WAF. The water layer is mixed with a chemical probe (i.e. benzoic acid) and then irradiated using a solar simulator. The amount of p-hydroxybenzoic acid (formed from hydroxy radicals and benzoic acid) is measured by UV detection-HPLC to determine hydroxyl radical
production rates.

Petroleum products are introduced into the environment through a variety of mechanisms and are shown to produce highly reactive oxygen species though photochemical reactions.1 One example is motor oil contamination which can come from sources including cars, trucks, and recreational water vehicles. Motor oils both synthetic and non-synthetic can produce potentially toxic components through natural weathering processes. To help assess overall ecosystem impact, a key consideration in understanding the mechanism of toxicity is examination of components produced through photochemical processes. Water accommodated fractions (WAFs) are samples of water mixed with oil and are commonly used to mimic environmental conditions when an oil spill occurs. Over time, water soluble species form and partition into the water phase of the WAF. This study examined photochemical degradation and subsequent toxicity of various synthetic oils when exposed to artificial sunlight for 6 hours. Benzoic acid served as a radical trap for any hydroxyl radical (·OH) species produced. Using high performance liquid chromatography (HPLC), the resulting formation of para-hydroxybenzoic acid (p-HBA) was measured and total ·OH flux determined.