Sample preparation procedure for the determination of polycyclic aromatic hydrocarbons in petroleum vacuum residue and bitumen (original) (raw)
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Fresenius' Zeitschrift f�r Analytische Chemie, 1984
Zusammenfassang. Zur Trennung der Erd61fraktion vom Siedebereich des Gas61s in die ein-, zwei-und dreikernigen aromatischen Bestandteile wird eine Gradientenelution an einer Aluminiumoxids/iule unter standardisierten Bedingungen angewendet. Zur Charakterisierung dienen UV-spektrometrische Messungen. Das Verfahren kann auch zur Untersuchung yon Aromaten aus anderen Erd61fraktionen eingesetzt werden. Summary. The method described is a simple procedure for separating gas oil boiling range petroleum fraction into its aromatic hydrocarbons of the mono-, di-and trinucleartype. This is accomplished by gradient elution through an alumina adsorption column under established/standardised conditions. Characterisation is performed by UV-absorption. The method can be used also for investigating aromatic hydrocarbon structures from other petroleum fractions.
2015
Polycyclic Aromatic Hydrocarbons (PAHs), which arise from incomplete combustion during engine operation, escape the combustion chamber, leading to lubricant contamination. PAHs have been declared highly detrimental to living organisms, and thus, PAH regulation in the environment is crucial because used engine oil accumulates PAHs in high levels. Engine oil samples were collected at different car maintenance workshops around Johannesburg, where the analysis of 5 target PAHs was carried out in both fresh and used engine oil samples (different oil bands), and then subjected to Gas Chromatography-Mass Spectrometry (GC/MS) and High Performance Liquid Chromatography (HPLC). In contrast to preliminary studies reporting higher PAH values of 300+ in used engine oil, the PAH value has decreased significantly, with PAH content being 70 and 7 times more in used engine oil by HPLC and GCMS respectively due to the different capabilities of the two instruments. Fourier Transform Infrared (FTIR) revealed evidence showing the formation of PAHs, which was corroborated by the presence of a band at 1600 cm-1 , which is associated with a CC stretch in a ring. In comparison to fresh oil, used oil quantitative proton Nuclear Magnetic Resonance (NMR) revealed a new intense peak at the aromatic region between 7-7.5 ppm, which may have arisen due to PAH formation. It was also observed that the PAH content was considerably lower compared to other constituents found in the oil sample. This drastic reduction in PAH concentration, may be due to the significant improvements made in lubricating (engine) oil formulations, refining processes, and engine designs. iii DEDICATION In memory of the fallen soldiers belonging to squad: Shakoane, Khumalo, Monareng and Mashego I would also like to extend my gratitude to the Chemical Industries Education and Training Authority (CHIETA) for funding both my research and coursework, the School of Chemistry and School of Chemical and Metallurgical engineering for their support and permission to use their facilities for analysis. I would also like to thank the personnel that took part to see through this study namely
A rapid method for polycyclic aromatic hydrocarbon determination in vegetable oils
Journal of Separation Science, 2002
Despite the carcinogenic properties of some PAHs, and although edible oils are particularly prone to PAH contamination, no international legal limits for PAH in edible oils have been yet established. However, a number of methods for such analyses have been published, most of which are time consuming and unsuitable for routine analysis, as they do not permit analysis of a large number of samples per day. Since sample preparation is the most time-consuming part of analysis, research to find fast sample preparation methods is of topical interest. In this paper, solid phase extraction with silica cartridges is applied as sole sample preparation step. A 250-mg sample of oil in n-hexane is loaded onto a 5 g silica cartridge and the PAH fraction is eluted with 8 mL of n-hexane/dichloromethane 70/30. After solvent evaporation, the volume was adjusted to 100 lL and injected into a HPLC equipped with a C18 reverse phase column and a spectrofluorometric detector. Results show a relatively low recovery for the more volatile PAHs (Na and Ac) and good recovery for heavy PAHs. Repeatability is quite satisfactory, as coefficients of variation range between 5.0 and 13.0%.
Evaluation of polycyclic aromatic hydrocarbons in gasoline by HPLC and GC-MS
Chromatographia, 2000
Summary In this paper the evaluation of polycyclic aromatic hydrocarbons (PAHs) in gasoline is described. A procedure involving a double extraction of samples with N-methylpirrolidone-water-phosphoric acid and with cyclohexane has been used followed by HPLC-DAD and GC-MS. The results obtained show that all gasoline samples contain PAHs with two to six rings and no substantial difference was noticed between leaded and
Journal of Chromatography A, 2007
An efficient and selective analytical method for the determination and the quantification of 19 polycyclic aromatic hydrocarbons (PAHs) in food and oil has been developed. This method includes the monitoring of 15 PAHs stated as a priority by the EU in their 2005/108 recommendation. The samples were extracted according to a selective extraction step using pressurized liquid extraction followed by a purification with polystyrenedivinylbenzene SPE. Identification and quantification were performed using GC-MS/MS, with an isotope dilution approach using 13 C-labelled PAHs. The novel combination of selective extraction followed by purification provides highly purified analytes combined to a fast and automated method. The advantages of GC-MS/MS as compared to other detection methods are tremendous in terms of sensitivity, selectivity and interpretation facilities. Limits of detection varied between 0.008 and 0.15 g kg −1 , limits of quantification between 0.025 and 0.915 g kg −1 for PAHs in food. The calibration curves showed a good linearity for all PAHs (R 2 > 0.99) and precision and recovery were fit for purpose. Trueness of the method was carried out using the US National Institute of Standards and Technology SRM 2977 reference material.
Journal of Separation Science, 2009
Pressurised liquid extraction (PLE) was applied to determine the atmospheric levels of 16 polycyclic aromatic hydrocarbons (PAHs) in the gas and particulate phases. The method involved high-volume air sampling with quartz fibre filters (QFFs) and polyurethane foam (PUF) plugs and analytes were subsequently extracted from the samples by PLE, and determined with GC-MS. We optimised the PLE conditions for the solvent, the number of cycles and extraction temperature. Recoveries were higher than 90% for most compounds. Method LODs and LOQs were between 0.001 and 0.02 ng/m 3 and between 0.01 and 0.05 ng/m 3. Air samples were taken from a site in the region of Tarragona in Catalonia, Spain, where one of the largest petrochemical complexes in southern Europe is located. The total concentration of PAHs were from 6.7 to 27.66 ng/m 3 , with predominant levels of PAHs appearing in the gas phase (48-81%), and an average level of benzo[a]pyrene, the most carcinogenic PAH, of 0.86 ng/m 3 .
Analytical Techniques for Identification and Quantification of Polycyclic Aromatic Hydrocarbons
2016
Several analytical techniques have been developed and applied for identification and quantification of polycyclic aromatic hydrocarbons (PAHs) present in different samples. These analytical techniques include gas chromatography coupled with flame ionization detectior (GC/FID), gas chromatography coupled with a mass spectrometry (GC/MS), high performance liquid chromatography (HPLC) coupled with an ultraviolet or fluorescence detector, and thin-layer chromatography (TLC) with fluorescence detection. Since sensitive analytical techniques were essential in the determination of the presence and levels of these toxic compounds, some aspects of standard preparation and suitable instrumental condition for quantification of the sixteen PAHs listed by the U.S. environmental protection agency (EPA) have been reviewed in this article. The quantification performance of each technique has been comparable for different samples matrix.
International Journal of Environmental Science and Development, 2012
Context and objective: The Migr'Hycar research project was initiated to provide decisional tools for risks connected to oil spill drifts in continental waters. This paper focuses on the distribution of polycyclic aromatic hydrocarbons (PAHs) from oils in water, air and oil slicks. Material and methods: Six petroleum oils covering a representative range of commercially available products were tested. Dynamic tests at laboratory scale were performed to study 41 PAHs and derivates, among them 16 EPA priority pollutants. Water soluble fraction protocol, stir bar sorptive extraction (SBSE) and high performance gas chromatography mass spectrometry (HPGC-MS) was used. Limit of quantification were lower than 1 ng.L-1 for each compounds. Results: A large variation in composition of the water soluble fraction depending on oil type and mixing time has been highlighted. Results have shown that evaporation is the primary mechanism of PAHs loss from spilled oil. The subsequent fate of hydrocarbons deposited in surface water is further influenced by volatilisation behaviour because of possible slick loss to the atmosphere. The water soluble fraction remains very low and is dominated by low molecular weight PAHS (e.g. naphthalenes).