Molecular and Isotopic Analysis of Motor Oil from a Biodiesel-Driven Vehicle

Abstract

Biodiesel, a mixture of fatty acid methyl esters (FAMEs), is increasingly recognized as a renewable fuel. While some environmental impacts of biodiesel usage have been investigated, accumulation of organic compounds in motor oil, which can subsequently leak onto roads, has not been studied. Because studies have shown that toxic polycyclic aromatic hydrocarbons (PAHs) accumulate in the motor oil of engines fueled with fossil diesel or gasoline, the objective of this study was to determine if this also occurs for engines fueled with biodiesel. Here, we sampled and analyzed motor oil of a biodiesel-powered 2005 Volkswagen Passat Wagon over 3240 km of personal-use driving. Using gas chromatography with flame ionization detection (GC-FID), we found a total of 0.5% FAMEs in the motor oil after 3240 km. We also used gas chromatography-mass spectrometry and comprehensive two-dimensional gas chromatography and did not detect PAHs or other organic compounds not present in the initial motor oil. Using natural radiocarbon analysis, a powerful technique capable of detecting biodiesel-derived carbon that would be otherwise undetectable by gas chromatography, we found a total of 0.68% biodiesel-derived carbon after 3240 km. This is similar to the amount of FAMEs found in these samples with GC-FID, indicating that the primary source of biodiesel-derived carbon in the motor oil is FAMEs (and not PAHs or other carbonaceous species). This result suggests that used motor oil of biodiesel vehicles can be less toxic based on PAH content than vehicles fueled with fossil diesel or gasoline.

Cyclodextrin-Enhanced Extraction and Energy Transfer of Carcinogens in Complex Oil Environments

“…This energy transfer was most efficient for motor oil, vegetable oil, and pump oil (with 360 nm excitation), and least efficient for cod liver oil. This data is consistent with literature reports of some degree of PAH contamination in motor oil, vegetable oil, and pump oil, and no PAHs in cod liver oil, [29][30][31][32][33] and supports the idea that PAHs in the actual oils participate in cyclodextrin-promoted energy transfer. To ensure that the fluorophore peak defined as energy transfer was a result of actual energy transfer from the analyte to the fluorophore (rather than a result of the fluorophore having a non-zero absorbance at the analyte excitation wavelength), the fluorophore was excited at the excitation wavelength of the analyte (270 nm, 290 nm, and 360 nm) in the presence of the analyte and in the absence of the analyte.…”

“…The oils used in these investigations (vacuum pump oil, motor oil, vegetable oil, and cod liver oil) contain varying levels of PAH contaminants: from no known PAHs in cod liver oil, 29,30 to small amounts of PAHs in several types of vegetable oil, 31,32 and large quantities of PAHs in used motor oil. 33 These 'innate' PAH amounts were detected by measuring the energy transfer efficiencies from 'undoped' oil samples to the fluorophore. Samples were separately 'doped' with small amounts of concentrated PAH solutions, which adds to the innate PAHs found in the oils and allows for a robust PAH-to-fluorophore energy transfer signal.…”

“…Reported herein is the successful implementation of a γ-cyclodextrin-based system to accomplish these two key functions: (a) extracting PAHs from complex oils and binding them with moderate to good efficiencies and (b) promoting noncovalent, proximity-induced energy transfer from the isolated PAHs to a high-quantum-yield BODIPY fluorophore. The oils used in these investigations (vacuum pump oil, motor oil, vegetable oil, and cod liver oil) contain varying levels of PAH contaminants: from no known PAHs in cod liver oil , to small amounts of PAHs in several types of vegetable oil , and large quantities of PAHs in used motor oil . These “innate” PAH amounts were detected by measuring the energy-transfer efficiencies from “undoped” oil samples to the fluorophore.…”

Uso da cromatografia gasosa bidimensional abrangente (GC×GC) na caracterização de misturas biodiesel/diesel: aplicação ao biodiesel de sebo bovino

“…Já a cromatografia gasosa bidimensional abrangente (GC×GC) é uma técnica que permite a separação dos picos de acordo com dois critérios diferentes, quais sejam a massa molecular ou ponto de ebulição e a polaridade, permitindo a total separação de hidrocarbonetos e ésteres. [17][18][19][20][21][22] É indicada para análise de misturas complexas na qual duas separações independentes são aplicadas para cada amostra. 2,12,15 A amostra é primeiramente separada na coluna convencional, passa por um processo de modulação e é submetida à outra separação em uma coluna da segunda dimensão, que é mais curta e com mecanismo de separação diferente (ortogonal) da primeira.…”

Toxicology of Biodiesel Combustion Products

“…It is unclear whether intact FAMES are emitted in the exhaust due to incomplete and /or poor combustion, but the possibility has implications for toxicity. Intact FAMES from biodiesel fuel can be released into the environment via 1) spills such as in the Black Warrior River in Alabama, USA (New York Times, 2008) and 2) the introduction of the fuel into lubrication www.intechopen.com oil, with subsequent leakage from the engine (Peacock et al, 2010); however the toxicity of biodiesel fuel not being combusted is not the focus of this chapter. Plant oils are utilized in biodiesel production on a commercial scale in the United States, though some biodiesel fuel can be produced from animal fats.…”