Proteomic analysis of the renal effects of simulated occupational jet fuel exposure

We analyzed protein expression in the cytosolic fraction prepared from whole kidneys in male Swiss-Webster mice exposed 1 h/day for five days to aerosolized JP-8 jet fuel at a concentration of 1000 mg/m3, simulating military occupational exposure. Kidney cytosol samples were solubilized and separated via large-scale, high-resolution two-dimensional electrophoresis (2-DE) and gel patterns scanned, digitized and processed for statistical analysis. Significant changes in soluble kidney proteins resulted from jet fuel exposure. Several of the altered proteins were identified by peptide mass finger-printing and related to ultrastructural abnormalities, altered protein processing, metabolic effects, and paradoxical stress protein/detoxification system responses. These results demonstrate a significant but comparatively moderate JP-8 effect on protein expression in the kidney and provide novel molecular evidence of JP-8 nephrotoxicity. Human risk is suggested by these data but conclusive assessment awaits a noninvasive search for biomarkers in JP-8 exposed humans.     

Phenomenological characterization and thermal analysis of flame spread over jet fuel: influence of radiant exposure time

Journal of Thermal Analysis and Calorimetry - The high-temperature objects widely exist in industrial and civil building such as the nearby burning pool fires, the heated walls and the hot smoke...     

民用航空煤油的化学组分分析

采用气相色谱-质谱联用法检测民用航空煤油溶液和蒸汽的化学组分,通过检索NIST 17.L标准谱库和比对标准物质的保留时间定性,使用峰面积归一化法确定各组分的相对含量并分析其健康效应.结果 表明,民用航空煤油溶液和蒸汽中的化学组分有差异,溶液中的碳数分布为C7-C15,主要包括烷烃,环烷烃,芳香烃,含氧、含氮化合物,会引...     

Chromatographic determination of copper speciation in jet fuel

A method is described that allows one to distinguish and quantitate two different classes of copper compounds in the same hydrocarbon sample. This will enable the study of the effects of different copper compounds on the performance and stability of petroleum samples. Copper N,N'-disalicylidene-1,2-propylenediamine (CuDMD) and several copper carboxylates were preconcentrated from a hydrocarbon matrix using a column packed with polyvinylpyrrolidone, (C(6)H(9)NO)(x), a novel polymeric stationary phase. The copper complexes were then sequentially eluted using a step gradient program beginning with hexane/isopropyl alcohol as the eluent and ending with an acetic acid/isopropyl alcohol eluent. The copper complexes were detected by serial UV absorbance and flame atomic absorbance (FAA) detection. With on-column preconcentration and FAA detection, the limits of detection were 7 and 40 ppb copper for CuDMD and the copper carboxylates respectively. With this method, it was possible to distinguish between the two different classes of copper compounds in the same hydrocarbon sample, which will help to provide an understanding of the catalytic activity of different copper compounds, leading to a better understanding of the factors causing fuel instability. The method promises to be a valuable tool in the analysis and characterization of copper compounds in petroleum samples.     

Determination of phenolic antioxidants in aviation jet fuel

The world-wide aviation jet fuel used for civil and military aircraft is of a kerosene type. To avoid peroxide production after the refinery process a specific antioxidant additive should be added on fuel. The antioxidants generally used are based on hindered phenols in a range of concentration 10-20 microg/ml. In the present work a specific method to measure the concentration of phenolic antioxidants is shown. The method is based on a liquid chromatographic technique with electrochemical detection. The technique, because of its selectivity, does not require sample pre-treatments. The analysis of a 5-10 ml fuel sample can be performed in less than 10 min with a sensitivity of 0.1 microg/ml and a RSD=2.5%. A comparison with another highly selective gas chromatographic technique with mass spectrometric detection with selected ion monitoring (GC-MS-SIM) is reported. The sensitivity of GC-MS-SIM method was 2 microg/ml with a RSD=3.1%.     

Corrosion analysis of graphite sinter as bipolar plates in the low-temperature PEM fuel cell simulated environments

Journal of Solid State Electrochemistry - The article presents the results of research and an analysis of the possibility of using sinters made of graphite powder as a material dedicated to the...     

Factorial discriminant analysis of occupational exposure in metallurgy using INAA of hair samples

A multivariate statistical technique-factoral discriminant analysis (FDA)-has been used to evaluate the occupational esposure of a group of metallurgy workers using the elemental composition of their scalp hair, as compared with a control group. The initial variables were the concentrations of ten minor and trace elements Al, Co, Cu, Fe, Mg, Mn, Sb, Se, V, and Zn determined in hair samples by using instrumental neutron activation analysis (INAA). A good discrimination between exposed and control subjects has been achieved after the normalization of the data (by log-transforming the initial variables) and considering sex-matched groups. To measure the accuracy of the classification and the predictive ability a cross-validation procedure was used.     

Uncertainty evaluation of the thermal expansion of simulated fuel

Thermal expansions of simulated fuel (SS1) are measured by using a dilatometer (DIL402C) from room temperature to 1900 K. The main procedure of an uncertainty evaluation was followed by the strategy of the UO₂ fuel. There exist uncertainties in the measurement, which should be quantified based on statistics. Referring to the ISO (International Organization for Standardization) guide, the uncertainties of the thermal expansion are quantified in three parts—the initial length, the length variation, and the system calibration factor. Each part is divided into two types. The A type uncertainty is derived from the statistical iterative measurement of an uncertainty and the B type uncertainty comes from a non-statistical uncertainty including a calibration and test reports. For the uncertainty evaluation, the digital calipers had been calibrated by the KOLAS (Korea Laboratory Accreditation Scheme) to obtain not only the calibration values but also the type B uncertainty. The whole system, the dilatometer (DIL402C), is composed of many complex sub-systems and in fact it is difficult to consider all the uncertainties of sub-systems. Thus, a calibration of the system was performed with a standard material (Al₂O₃), which is provided by NETZSCH. From the above standard uncertainties, the combined standard uncertainties were calculated by using the law of a propagation of an uncertainty. Finally, the expanded uncertainty was calculated by using the effective degree of freedom and the t-distribution for a given confidence level. The uncertainty of the thermal expansion for a simulated fuel was also compared with those of UO₂ fuel.     

Toxicity of chemical mixtures: proteomic analysis of persisting liver and kidney protein alterations induced by repeated exposure of rats to JP-8 jet fuel vapor

Male Sprague-Dawley rats were exposed by whole body inhalation to 1000 mg/m3 +/- 10% JP-8 jet fuel vapor or room air control conditions for 6 h/day, 5 days/week for six consecutive weeks. Following a rest period of 82 days rats were sacrificed, and liver and kidney tissues examined by proteomic methods for both total protein abundance and protein charge modification. Kidney and lung samples were solubilized and separated via large scale, high resolution two-dimensional electrophoresis (2-DE) and gel patterns scanned, digitized and processed for statistical analysis. Through the use of peptide mass fingerprinting, confirmed by sequence tag analysis, three altered proteins were identified and quantified. Numerical, but not significantly different increases were found in total abundance of lamin A (NCBI Accession No. 1346413) in the liver, and of 10-formyltetrahydrofolate dehydrogenase (10-FTHF DH, #1346044) and glutathione-S-transferase (GST; #2393724) in the kidneys of vapor-exposed subjects. Protein charge modification index (CMI) analysis indicated significant alterations (P < 0.001) in expressed lamin A and 10-FTHF DH. These persisting changes in liver and kidney proteins are discussed in terms of possible alterations in the functional capacity of exposed subjects.     

Quantitative analysis of barium and strontium in simulated oxide fuel during electrolytic reduction and salt distillation

Barium and strontium contents of alkaline-earth fission products in simulated oxide fuel were quantitatively analyzed during electrolytic reduction and salt distillation. Electrolytic reduction of the simulated oxide fuel was conducted at 650 °C in molten Li₂O–LiCl salt. The residual salt was then separated by salt distillation at 900 °C. Ba and Sr were partially separated from the simfuel and accumulated in the salt during oxide reduction. Ba and Sr levels of 0.21–0.56 wt% of their initial simfuel masses were found in the distilled salt; 2.28–3.34 wt% were found in the fuel remaining after the salt distillation.     

Assessment of occupational exposure and contamination

In order to assess the elemental concentration level in a galvanizing industry and alert for the need to assess the outcome of a long-term exposure, scalp hair and toenail samples were used as bioindicators and the industry environment was evaluated through airborne particulate matter. The elemental concentration results have pointed out a high exposure to pollutant at workplaces and a high elemental concentration in biomonitors suggesting endogenous contamination. The majority of the elements determined in airborne particulate matter were also determined in hair and toenail samples. The results evidence the efficiency of these matrixes as biomonitors and the importance to carry out the airborne particulate matter sampling in parallel to these biomonitors mainly in occupational epidemiological studies.     

Theoretical design and preparation of high thermal-stable jet fuel

A high thermal-stable jet fuel design method was developed using composition-properties relations and basic specification properties of jet fuel. Tannery diagrams were provided to visualize relationships among three main components (n-paraffins, iso-paraffins, cycloparaffins, or aromatics) with four major specification properties (density, flash point, freezing point, net heat of combustion) and thermal sta- bility. An optimum chemical composition was established to meet performance requirements: n-paraffins 25%-45%, iso-paraffins 15%-30%, cycloparaffins 30%-50%, and aromatics 5%. The thermal stability test on four fuel samples with and without optimal composition indicated that the thermal stabilities of fuel samples with optimal composition are higher than RP-3 jet fuel, and that the theoretical design method is a reliable method to screen the basic oil for the high thermal-stable jet fuel.     

Determination of elemental sulfur in jet fuel by differential pulse polarography

A sensitive method based on differential pulse polarography is described for the determination of elemental sulfur in jet fuels. Its sensitivity makes it suitable for following small changes in the sulfur content of jet fuel during storage. The supporting electrolyte is 0.19 M ammonium acetate/0.088 M acetic acid in 1:1 toluene/methanol. In this medium, the peak potential is ?0.56 V vs. Ag/AgCl. Calibration is linear from 2 to 30 mg l^?1. The limit of detection is 0.1 mg l^?1. Accuracy is better than 5%. Interferences from oxygen, hydrogen sulfide, thiols, organic sulfides and disulfides, organic peroxides and fuel additives are shown to be of very minor significance.     

Determination of total and polycyclic aromatic hydrocarbons in aviation jet fuel

The aviation jet fuel widely used in turbine engine aircraft is manufactured from straight-run kerosene. The combustion quality of jet fuel is largely related to the hydrocarbon composition of the fuel itself; paraffins have better burning properties than aromatic compounds, especially naphthalenes and light polycyclic aromatic hydrocarbons (PAHs), which are characterised as soot and smoke producers. For this reason the burning quality of fuel is generally measured as smoke fermation. This evaluation is carried out with UV spectrophotometric determination of total naphthalene hydrocarbons and a chromatographic analysis to determine the total aromatic compounds. These methods can be considered insufficient to evaluate the human health impact of these compounds due to their inability to measure trace (ppm) amounts of each aromatic hyrcarbon and each PAH in accordance with limitations imposed because of their toxicological properties. In this paper two analytical methods are presented. Both are based on a gas chromatographic technique with a mass detector operating in be selected ion monitoring mode. The first method was able to determine more than 60 aromatic hydrocarbons in a fuel sample in a 35-min chromatographic run, while the second was able to carry out the analysis of more than 30 PAHs in a 40-min chromatographic run. The linearity and sensitivity of the methods in measuring these analytes at trace levels are described.     

Chemical oxidative degradation of Polybenzimidazole in simulated environment of fuel cells

The chemical oxidative degradation process of poly [2,2′-(m-phenylene)-5,5′-bibenzimidazole] (PBI) in simulated environment of fuel cells was evaluated. From the mechanical properties and the intrinsic viscosity of PBI, it was observed that the stress at break of PBI membranes decreased and the macromolecular chains of PBI were broken after the treatment in Fenton reagent for 24 h. From the photos of Scanning Electron Microscope, it was identified that there were lots of corroded holes in PBI membranes. By means of FTIR and ¹H NMR analysis, it was shown that during the treatment of PBI in the presence of HO or HOO free radicals the hydrogen atom of N-H bond in imidazole ring was liable to be oxidized, and the phenyl was oxidized with the formation of quinine and dicarboxylic acid structures. In the end, the possible mechanism of the chemical oxidative degradation of PBI was proposed.     

Synthesis of jet fuel through the oligomerization of butenes on zeolite catalysts

In this study, the oligomerization of a butene mixture composed of 1-butene, cis-2-butene and trans-2-butene over several types of zeolites in a fixed-bed catalytic reactor at an elevated pressure was studied to produce hydrocarbons in the jet fuel range (C₈–C₁₆). Three types of zeolites, HZSM-5, Hβ and HY, were compared to evaluate the performance during the synthesis of jet fuel via the oligomerization of the aforementioned butene mixture. Compared to HY and Hβ, HZSM-5 showed a very stable butene conversion rate with high selectivity to jet-fuel-range hydrocarbon, which could be attributed to high resistance to coke resulting from the pore structure. HZSM-5 (50) shows the best quantitative conversion performance and yield for jet fuel for a time-on-stream of up to 6 h. It was also noted that the branched-to-linear hydrocarbon ratio reached 8.7 over the HZSM-5 (50) catalyst, which is beneficial to improve the cold properties of jet fuel. The present study reveals that HZSM-5 (50) is a potential catalyst for jet fuel synthesis through the oligomerization of butene mixture, exhibiting high stability and a high yield.     

Rapid determination of desorption efficiency, and analysis of solvent mixtures for occupational exposure studies

Summary An analytical procedure has been developed for simultaneous determination of solvent mixture vapors to enable evaluation of occupational exposure. To determine the desorption efficiency the volatile components of the solvent mixtures were generated from a glass tube filled with glass wool. This device is easy to prepare and use. These vapors were then collected in activated charcoal tubes and analyzed by capillary gas chromatography. The method was tested with a mixture of 22 solvents, including aliphatic and aromatic hydrocarbons, alcohols, ethers, esters, and ketones, all at low concentrations. All the components were detected. When a 99∶1 mixture of carbon disulfide-dimethylformamide was used for desorption the efficiency was>75% for most of the solvents.     

Proteomic analysis of the Arabidopsis thaliana cell wall

With the completion of the Arabidopsis genome, many hypothetical proteins have been predicted without any information on their expression, subcellular localisation and function. We have performed proteomic analysis of proteins sequentially extracted from enriched Arabidopsis cell wall fractions and separated by two-dimensional gel electrophoresis (2-DE). The proteins were identified by peptide mass fingerprinting using matrix-assisted laser desorption/ionisation-time of flight (MALDI-TOF) mass spectrometry and genomic database searches. This is part of a targeted exercise to establish the entire Arabidopsis secretome database. We report evidence for new proteins of unknown function whose existence had been predicted from genomic sequences and, furthermore, localise them to the cell wall. In addition, we observed an unexpected presence in the cell wall preparations of proteins whose known biochemical activity has never been associated with this compartment hitherto. We discuss the implications of these findings and present results suggesting a possible involvement of cell wall kinases in plant responses to pathogen attack.     

Improved HPLC methodology in occupational exposure studies on formaldehyde

Summary This work describes an HPLC method for the determination of formaldehyde concentration in air. Traps containing 20–40 mesh silica gel coated with 2,4-dinitrophenylhydrazine (DNPH) are used. After aspiration of air the traps are eluted with methanol. The hydrazone formed is then separated on a C18 column using a mobile phase of methanolwater (50–50 v/v). The effluent is monitored with a UV detector at 365 nm. To calibrate and to compare this method with that of Niosh 2502 (traps coated with 2 benzylamino ethanol on Chromosorb 102), a mixing chamber that generated atmospheres of known concentration of formaldehyde was used.