Benzene calibration curve

It is obvious that Figure 3-6 serves as a calibration curve with the help of which the chlorine content of unknown, similar materials could be readily determined. It will now be shown that the solid line agrees closely with kf values calculated from the mass absorption coefficients of benzene, hydrogen, and chlorine small variations in effective wavelength will be disregarded. 

Field Tests. Recently we conducted a field test at a site contaminated with fuel oil. Our measurements were 0.0625 0.0212 mA for the well water and 0.0189 0.0119 mA for distilled water (showing errors of one standard deviation). From calibration curves, these numbers can be reported as equivalent to 50 ppb phenol or 34 ppb xylenes. Nine-month-old laboratory results (EPA method 624 and GC/FID) for this site indicated concentrations of 25 ppb for benzene, toluene, and xylenes combined and 100 ppb for fuel oil. The important result is the significant difference between the distilled-water and well-water measurements. We are very encouraged by these results and are planning future field tests. 

Plot a calibration curve between the observed temperature-rise in a 3 minute interval Vs percent benzene present in cyclohexane. Run pure cyclohexane and standards containing 0.5-5.0 percent... 

Apparent values calculated on the basis of the extrapolated polystyrene calibration curve for 106A pore-size 20/i particle poly(styrene-divinyl-benzene) column. 

The ordinate in Figure 8.4b gives the ratio of the intensity of the solvent-induced band relative to the intensity of the major peak at a 3.6-nm shorter wavelength. With this as a calibration curve, the behavior of the benzene in the sodium dodecyl sulfate micelles can be interpreted in terms of the micellar microenvironment of the benzene molecules. In this case the microenvironment is about 62% of the way between hydrocarbon and water. 

Figure 3 indicates how well this aromaticity calibration curve is reproduced by C13 measurements on a series of benzene-cyclohexane blends. Here the dotted line is the calibration curve shown previously (Figure 2), while the solid line passes through the experimental points for the blends. The difference between the two curves is about 2%. 

Carbon contaminated surfaces were prepared by thermally decomposing benzene on the nickel surface. The carbon overlayer was ordered but the diffraction pattern was complex. It did not correspond to a graphitic ring structure. Approximate carbon coverages were estimated using Auger calibration curves based on thermally decomposed benzene (10). 

The solvents dioxane from Merck, /-BuOH, z-PrOH, benzene and 1,2-dichloroethane from Baker, diglyme from ACROS. During the reaction samples were taken from the reaction mixture and analyzed by capillary GC (CP Wax 52 CB) and GC-MS. GC Calibration curves were made with mixtures of authentic samples and l,3,5-tri-/er/-butylbenzene as internal standard. 

What is the concentration of benzene in the sample Prepare a spreadsheet similar to the one described in the chapter, and print the calibration curve. 

Fig. 6(a) HPLC chromatograms of. samples at different eoneentrations. (b) Plots of the wavelet eoefficients D obtained by decomposing of one of the samples in (a) using the Harr wavelet function. (c) A plot of the wavelet coefficients Dj- of all the samples in (a), (d), A plot of the baseline-corrected wavelet coefficients Dj-j of all the samples in (a), (e) Calibration curve of. samples in (a) (i) benzene, (iij methybenzene, and (Hi) ethylbenzene. Reproduced from reference [29] with the kind permission of the American Chemical... 

Fig. 7. Calibration curve for the extinction coefficient of benzene sorbed into zeolite H-ZSM-5 integrated absorbance of the typical benzene band at 1478 cm" vs. the barometrically measured amoimt adsorbed [132]...

The maleic acid used to quantitate ibuprofen as described above is an example of an internal standard. Such standards are added at a known concentration to a fixed sample volume in the NMR tube. KHP, maleic add, and trimethylsilylpropionic acid (TSP) are common standards for aqueous samples, while cyclohexane or benzene are suitable for samples soluble in organic solvents. A more comprehensive list of standards has been provided by Kasler. This is a convenient way to perform quantitative analyses as additional solutions (e.g., those required when generating a calibration curve for other methods) are not necessary, although the sample is contaminated by the internal standard. 

FIGURE 2. Calibration curve - weight of benzene vs. net instrument response. 

FIGURE 52 2 Typical calibration curves for various mixtures of methanol, acetaldehyde, acetone, isoprene, benzene, and styrene between 0 and 80 ppbv. 

The molecular interactions were evaluated by FTIR spectroscopy. As an example, Figure 5 shows the FTIR spectrum of the insoluble PP residue from the extracted blend, after modification by BMI. Typical absorption bands of PS occur in the PP spectrum at 1601 cm and 699 cm caused by absorption of the skeleton oscillations of the benzene ring and the absorption of the aromatic substitution on it. This indicates that PS chains are grafted onto the PP molecules. Hence, no absorption band occurs in the FTIR spectrum of the unmodified PP/PS blend. For quantification of the grafting, the PS content was estimated from the area under the peaks at 1601 cm and 699 cm using a calibration curve. The amount of the grafted PS strongly depends on the BMI, but not as much on the DCP content. For example, at 1 wt% of BMI in the blend up to 2.5 wt% of... 

Rapid determination of methylmercury salt in liver. Follow cysteine acetate procedure only adding Ig of molybdic acid/lOg of sample to the liver suspension and shake for 30 seconds. Then add the sodium chloride, hydrochloric acid and benzene at once. Shake and centrifuge immediately. When preparing the calibration curve according to this procedure, add the methylmercury salt immediately beofre the first extraction with benzene. 

A gas chromatogram of the reaction products obtained from DC 704, a polymethylphenylsiloxane, is shown in Figure 103. Methane and benzene are the only volatile reaction products observed the water is liberated from the reagent. Calibration curves were initially prepared using benzene and GE Viscasil 60,000 as standards. 

Using the flame ionization detector and temperature programming Veening et al obtained results quoted in Table 149 for a mixture of five areue tricarbonylehromiurn compounds. Except where indicated the mesitylene compound was used as reference compound for quantitative analysis. Calibration curves for all four constituents were linear between 1.0 x 10 and 1.0 x 10 g/ml. From the results in Table 149 it can be seen that the accuracy of the method is good to within i 3.2% relative error. Table 149 also tabulates results obtained for benzene and mesitylene tricarbonylchromium using an electron capture detector and 2-bromonapthalene as internal standard. 

Some simple quantitative measurements are also possible. Galloway and co-workers [7] demonstrated a calibration curve for benzene-chloroform mixtures based on relative... 

Prepare Solution 3 containing approximately 40 pg of thiophene per millilitre by pipetting 2 mL of Solution 1 into a 100-mL volumetric flask and diluting to volume with thiophene-free benzene. Follow the procedure in 10.2 to obtain the calibration curve for 50-mL specimens. 

Determine the concentration of thiophene from the calibration curve (Section 10). If the absorbance is greater than 1.5, repeat the procedure using a 50-mL specimen instead of 100 mL. If the 50-mL specimen still gives absorbance above 1.5, then the specimen must be diluted with thiophene-free benzene before proceeding. 

Calculate the ratios of the peak areas of benzene and toluene to the peak area of MEK. Read from the appropriate calibration curve the liquid volume percent of benzene and toluene corresponding to the calculated peak ratios. 

Typical Calibration Curve for Benzene (Determine for Each Analytied Syetam)... 

Calculate the benzene content of the gasoline in liquid volume percent by entering the calibration curve of... 

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