Gasolines gasoline samples

Although gas chromatography can give the concentration of each component in a petroleum gas or gasoline sample, the same cannot be said for heavier cuts and one has to be satisfied with analyses by chemical family, by carbon atom distribution, or by representing the sample as a whole by an average molecule. 

The aim of this work is the development of pyrene determination in gasoline and contaminated soils. For this purpose we used room temperature phosphorescence (RTP) in micellar solutions of sodium dodecylsulphate (SDS). For pyrene extraction from contaminated soils hexane was used. Then exttacts earned in glass and dried. After that remains was dissolved in SDS solution in the presence of sodium sulphite as deoxygenation agent and thallium (I) nitrate as heavy atom . For pyrene RTP excitation 337 nm wavelength was used. To check the accuracy of the procedures proposed for pyrene determining by RTP, the pyrene concentrations in the same gasoline samples were also measured by GC-MS. 

Methyl alcohol can be used as a fuel instead of, or combined with, gasoline. A sample of methyl alcohol, CH3OH, in a flask of constant volume exerts a pressure of254 mm Hg at 57°C. The flask is slowly cooled. 

Gasoline-air mixtures tend to ignite prematurely, or knock, rather than bum smoothly. The octane number of a gasoline is a measure of its resistance to knock. It is determined by comparing the knocking characteristics of a gasoline sample with those of isooctane (the common name of one of the isomers of octane) and heptane ... 

Consult your instructor for proper separation conditions. Obtain a chromatogram of the gasoline sample and locate the peak to be identified and quantitated. Identify this peak by matching retention times with some pure samples, or consult your instructor. 

Figure 4.15a are LNAPL obtained from two adjacent sites with different histories, and representative unaltered regular unleaded and premium unleaded gasoline samples. High BTEX hydrocarbon concentrations in LNAPL and groundwater are often indicative of gasoline presence. A noticeable depletion in benzene and toluene is evident in the LNAPL samples as compared with unaltered dispensed gasoline,... 

Harley, R.A. and Coulter Burke, S.C. Relating liquid fuel and headspace vapor composition for California reformulated gasoline samples containing ethanol. Environ. Sci Technol, 34(19) 4088M094, 2000. 

To resolve the problem, personnel from the gasoline additive supplier worked with the customer to collect service station gasoline samples, customer fuel filters, and samples of gasoline from the retailer s local service stations and from the fuel distribition terminal. All of these samples were thoroughly analyzed. Also, January fuel delivery records were closely audited. 

Table XII. Precision on NBS—EPA Round-Robin Gasoline Sample Counting Standard Precision ...

In the case of zeolite U1F-25S, the results from Figure 6 show that this sample produces less gases and coke and more gasoline than sample USY-3. These results would be in agreement with the hypothesis made above, that alumina type EFAL, while being active for bottoms conversion is less selective for gasoline and more selective for gases and coke. 

The feed used was an FCC gasoline sample obtained from a European refinery and was subsequently distilled to give an approximate boiling range of 35-190°C. 

The robustness of RSIMPLS is illustrated on an octane data set [67] consisting of NIR absorbance spectra over p = 226 wavelengths ranging from 1102 nm to 1552 nm, with measurements every 2 nm. For each of the n = 39 production gasoline samples, the octane number y was measured, so q = 1. It is known that the octane data set contains six outliers (25, 26, 36-39) to which alcohol was added. From the R-RMSECV values [68], it follows that k = 2 components should be retained. 

Dual Detectors. Most dual detectors are run in parallel, the column effluent being split and run through both of them simultaneously. In GC the technique is known as dual channel GC usually, one of the detectors chosen is universal and the other is highly selective. Figure 6.6 shows the analysis of a commerical gasoline sample with dual detection by flame ionization (FID) and electron capture (ECD). The FID detects all the hydrocarbons, but the ECD is selective for the alkyl lead additives in gasoline and permits their detection without interference from the hydrocarbons. 

Figure 6.6. Dual channel presentation of GC analysis of gasoline sample on a packed DC-200 column. Courtesy of Perkin-Elmer Corp.

Gasoline Dilute sample with hexane GC/FID NR NR Poole et al. 1988... 

Gasoline Dilute sample with methanol elute benzene to analytical column with 50% methanol back-flush guard column with 100% methanol HPLC/UV NR NR Ludwig and Eksteen 1988... 

Alkyl Pb compounds, mainly tetramethyl and tetraethyl Pb, are added to gasoline as anti-knock agents. The amount added varies from country to country but is generally in the range 200—1500/igml-1 Pb and this may be present as one or both of the Pb alkyl species mentioned. Unfortunately, it has been found that the Pb response in atomic absorption spectroscopy is dependent on the particular alkyl with which it is associated. Thus, unless it is known that only one particular Pb alkyl is present in a gasoline sample, it is not possible to employ a simple dilution procedure. Since the exact nature of the Pb species is seldom known for sure, then a general analytical method must ensure that the response from the various Pb alkyls is equalised in some manner. This is achieved by stabilisation with iodine and a quaternary ammonium salt. 

The method is suitable for the determination of Pb in gasoline in the range 1—lOOOpgml-1 (0.001—1 gl 1). The gasoline sample is diluted with MIBK and shaken with a solution of iodine in toluene. Iodo lead alkyl species are formed and these are stabilised with a liquid anion exchanger. Thus, the problem of the variable Pb response is overcome. This solution is compared with standards prepared in a similar fashion from Pb chloride in MIBK. 

Figure 7.7 Boiling point distribution of liquid fuel formed over US-Y zeolite, a commercial cracking catalyst, a pillared clay (polymer-to-catalyst ratio 2 1) and comparison with a commercial gasoline sample...

Fignre 7.7 compares the boiling point distribution of liqnid products formed over US-Y, a commercial cracking catalyst and a pillared clay. In the same figure is plotted the boiling point distribution of a commercial gasoline sample. 

There are limited data on the distribution pattern of gasoline in humans and animals. The distribution of gasoline (gasoline concentration measured as the ratio of the concentrations of [2-methylpentane/2,2-dimethylbutane] in sample/[2-methylpentane/2,2- dimethylbutane] in standard) was determined in a male who died following accidental ingestion of gasoline (Carnevale et al. 

Russo PJ, Florky GR, Agopsowicz DE. 1987. Performance evaluation of a gasoline vapor sampling method. Am Ind Hyg Assoc J 48 528-531. 

Gasoline samples, a variety of gasolines, kerosenes, lighter fluids store in small plastic vials. 

Quantitative recovery of selenium was verified for a gasoline sample spiked with a known amount of selenium as dilaurylselenide and a mineral oil (white oil) spiked with dilaurylselenide and selenium dioxide. The samples were oxidized under total reflux, and the selenium was measured by the hydride generation-atomic absorption technique. Quantitative recovery of the added selenium indicated that selenium is not lost during sample preparation (Table 15.1). 

Let us consider a data set containing Near-Infrared (NIR) spectra of 30 gasoline samples and five dependent variables (Y = [yl y2 y3 y4 ySj) [31], The original spectra and the so-called std spectrum are presented in Fig. 2. The std, i.e. standard deviation, spectrum it is a vector, the elements of which... 

Ethanol (C2H5OH), a domestically produced fuel source, is often blended with gasoline. A sample of ethanol has a mass of 45.6 g. 

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