Gasoline samples, comparison

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...

The accuracy and bias of the analyzer was evaluated using three NIST SRMs and a commercial gravimetric standard. One specimen was taken from each sample and 10 readings were recorded. The mean of the 10 data points was obtained and was compared with the reference value. The comparison is shown in Table 8. Biases for these reference samples were found to be non-significant except for the gasoline sample. 

Sandercock, P.M.L., DuPasquier, E. (2004) Chemical fingerprinting of gasoline. 3. Comparison of unevaporated automotive gasoline samples from Austraha and New Zealand. Forensic Sci. Int., 140(1), 71-77. 

FIGURE 13.39 Comparison of chemiluminescence detector response with an FID on a heavy diesel sample and a regular unleaded gasoline sample. (Reproduced with permission from Reference 106, ANTEK Instruments, Inc.)... 

FIGURE 13.60 Comparison of a traditional (a) and fast (b) process gas chromatogram for an ASTM D3710 standard as well as a gasoline sample. (Reprinted from Reference 136 with permission from ABB Automation, Inc., Lewisburg, WV 24901.)... 

Comparison of Gasoline Samples EXPLOSIVES ANALYSIS WITH GAS CHROMATOGRAPHY... 

The overall method for gasoline requires no sample preparation other than the addition of internal references. The method is fast since samples may be run at 3-min intervals, interference-free and specific for MMT. Analysis time comparison is favourable with respect to atomic absorption analysis which typically required about 15 min per sample when run in batches. Further, the procedure is readily adapted for use with open tubular columns. Porous layer open tubular columns (PLOY) are best suited to accommodate the direct injection of gasoline samples. The improvement in analysis time for MMT determination by the latter method may outweigh the somewhat poorer limit of detection resulting from limitations on the sample size. 

In the round-robin analysis, a minimum of five samples each of coal, fly ash, gasoline, and fuel oil were analyzed. The NBS Probable Certified Value for certain elements are shown in Table IX along with PBR values. Since no data were reported on gasoline, there are no comparisons. The most inconsistent comparison was for mercury. Only four laboratories reported mercury by INAA in coal, three by INAA in fly ash, and two by INAA for fuel oil. Most other laboratory results reported were based on atomic absorption spectrometry. With one exception, all mercury values reported by INAA (a nondestructive method) were higher than... 

Springer (5) using a sampling probe-impactor system for a similar cruise condition with an eight-cylinder Chevrolet engine. The reported im-pactor data, taken on a mass basis, was converted to a number basis here assuming a particulate density of 1.8 g/cm and normalized to gasoline consumption to facilitate comparison. 

A similar analysis for Pb yields the following results icesheet concentration ratio is about 15 and atmospheric emission ratio is about 20. While this is not too bad a comparison, it is not as good as for the other three metals (Zn-Cd-Cu). It is clear that most of the Pb increase in snow/ice samples from Greenland is due to the use of leaded gasoline after the 1950s (Murozumi et al., 1969). 

As metallation proceeds the product selectivity changes. The coke factor (defined in Table 2) in sample CD increases from 1.5 at 8 hours to 2.1 at 24 hours operation. The gas factor changes from 0.6 to 1.1 for the same period of time. By comparison, factors for ECAT and HTD (1.4 and 1.5) and gas factors (1.3 and 0.6) are almost constant. The gasoline selectivity varies from 67 to 75% for sample CD, 62 to 64% for sample HTD and remains almost constant 69-70% for sample ECAT2. 

FBR Lab- and field scale (comparison) Various sources including gasoline-contaminated soil and water samples Groundwater treatment [100]... 

Comparison of hydrocarbon composition of gasoline, fuel evaporate, exhaust, and ambient air sampled in Los Angeles. Adapted from data presented by Glasson and Tuesday (1970), Heaton and Wentworth (1959), Kopczynski et al. (1972), Leach et al. (1964), Lonneman et al. (1974), Maynard and Sanders (1969), McEwen (1966), Stephens et al. (1958), Stephens and Burleson (1967), and Tuesday (1976). h Percent of total hydrocarbons. 

Slovak Republic in the framework of the PHARE Project (1996-1997) (Table 7). Considering the situation in Slovakia, all the mean levels from all the sampling sites were below the annual National Ambient Air Quality Standards (0.5 p.g/m ) and guideline by WHO. Comparison with typical values for atmospheric lead levels in Europe indicates that, in general, the levels measured in Slovakia are at the lower end of typical European levels (Ursmyova and Hladikova, 1998a). Cities in Slovakia show the relationship between the decreasing use of lead in gasoline and the decline in airborne lead concentrations (Fig. 2) (Violova et al., 1997). 

Figure 10.4 Comparison of recovery by 3 heated head-space enrichment methods. Sample Fire debris sample, gasoline on a charred matrix of carpet and carpet padding (Instrument 1). Top SPME, Car-boxen/PDMS fiber (70°C, 3 min extraction). Middle Static headspace enrichment (90°C,...

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