Peak deconvolution

FIGURE 10.6 2D differential display of CF fractions from M4A4 and NM2C5 secreted samples. These fractions ranged in pH from 5.6 to 5.4. The differential display map was created using point-by-point subtraction of the areas of the deconvoluted peaks in the TIC. (See color plate.)... 

Both type I and type II water forms were detected, and the I/II mole ratio was rather constant at 1 2.2 for the Na+ form having the low H2O/SO3 mole ratios of 0.06, 0.5, and 1.2. These numbers were derived from the areas under the two deconvoluted peaks. The ratio of type I to II water molecules decreases in the order for the series Na+ > K+ > Rb+ > Cs+, which is reasonable considering that the cation hydration number decreases in this order and shows the structure-breaking action of cations with... 

In our ease the hydrogen eonsumption of the former deconvolution peak is always indicating a reduction exceeding the mere Co Co. At one hour of grinding time sample BOl shows a 17.5% eonversion to the metal, whieh first increases to 31% after two hours (sample B02) and then deereases regularity to 13.7% after 10 hours of milling (sample BIO). The citrate sample, with the lowest surface area (see Table 1), yields only 2.3% conversion to the metal. Obviously some Co must be aheady formed at this intermediate temperature, well below the seeond peak eorresponding to the complete Co Co reduction of the bulk cobalt. 

Fig. 11. High-resolution 29Si MAS NMR spectra of synthetic zeolites Na-X and Na-Y at 79.80 MHz (58). Experimental spectra are given in the left-hand columns Si(nAl) signals are identified by the n above the peaks. Computer-simulated spectra based on Gaussian peak shapes and corresponding with each experimental spectrum are given in the right-hand columns. Individual deconvoluted peaks are drawn in dotted lines.

In figure 14.11, the C Is XPS spectra are given of the aminopropylsilica at different stages of thermal treatment. Experiments were performed using silica coated with a polymerized silane layer. Deconvoluted peak positions and relative percentages are indicated in the figure. 

In addition, even if manual measurements are employed, a separation of 6a is far more than necessary for accurate quantitative analysis. In fact, accurate quantitative results can be obtained with a separation of only 4a and it will be shown later that if peak heights are employed for quantitative measurement, then even less resolution may be tolerated. Duplicate measurements of peak area or peak height on peaks separated by 4a should not differ by more than 2%. If the chromatographic data is acquired and processed by a computer, then with modern software, even a separation of 4a could be more than necessary. Poor resolution can often be accommodated by deconvoluting the peak and measuring the peak heights or areas of the deconvoluted peaks. 

It is seen that two Gaussian shaped peaks can be easily extracted from the composite envelope and the software could also supply values for either the heights of the deconvoluted peaks or their area. It should be noted, however, that the two peaks are clearly discernible and the deconvoluting software can easily identify the approximate positions... 

Figure. 44 shows the C Is (a-d), O Is (e-h), and Fe 2p 2 (i-j) XPS peaks of CWZ (NM and Ox) samples with adsorbed iron ions. There were marked differences between the experimental (dotted) and synthesized (continuous) lines in all the spectra. The position of deconvoluted peaks (dashed lines) were determined according to both literature data [188,191,240-247] and empirically derived values. The relative areas (%) of the fitted peaks were also calculated. Several peaks attributable to carbon, oxygen, nitrogen, and iron were present. The XP survey spectra of the initial modified carbons (before adsorption) were discussed... 

Fig. 4 CPMAS NMR spectrum of a 1 1 (wt/wt) mixture of neotame form G and amorphous neotame. Inset shows expansion of the aromatic region of the spectrum with the deconvoluted peaks used for quantitation. Relative peak areas are shown. (From Ref. l)...

Figure 5. ESC A spectar of POP film (a) unetched (b) oxygen plasma-etched. Solid lines measured peaks dashed lines represent deconvoluted peaks.

For the 1 - 7TiSi samples, however, a positive shift of -0.5 eV in the BE values of Ti2p compared to that of pure titania were detected [4]. The values stayed within the range of 459.3 0.2 eV, independently of the surfece coverage. When the 01s peak arising from pure silica was fixed at 532.8 eV, the lower peak maxima of the deconvoluted peak decreased, as a fimction of the titania concentration, from 531.1 eV (contribution 10 %) to 530.8 eV (contribution 35 %) (Fig. 4). The difference between the two 01s peak maxima was smaller, from 1.7 to 2.0 eV, than for the mix-TiSi sample. The results indicate the... 

I is the bound state resonance intensity, the integrated area of a normalized and deconvoluted peak... 

A priori, one way to correlate H and X NMR spectra is to examine the effect of some systematic chemical treatment on both types of spectra. Maciel and coworkers [59] have explored the effects of silylation with the reagent CHD (CD3)2SiCl on the H CRAMPS and Si CP-MAS spectra of silica gel. The spectra are shown in Fig. 23. After deconvolution and an attempt to correct the intensities of the deconvoluted peaks for differences in relaxation properties, it appeared that the H CRAMPS peak identified with hydrogen-bonded silanols correlates chemically with the Si CP-MAS peak identified with single silanols. In addition, the H CRAMPS peak identified with isolated (non-hydrogen-... 

Figure 25 Plots of deconvoluted peak integrals of the 39.75 MHz Si CP-MAS NMR spectra of Fisher S-679 silica gel vs. H- Si dipolar-dephasing time up to four rotor perkxJs. CP contact time, 5 ms magic-angle spinning speed, 2.0 kHz. Vertical da.shed lines show odd numbers of rotor periods, and vertical solid lines show even numbers of rotor periods, (a) - 89 ppm peak (geminal silanols) (b) -99 ppm peak (single silanols) (c) - 109 ppm peak (siloxane silicons). (From Ref. 60.)...

An analogous set of results, given with computer-deconvoluted peak contributions, is shown in Figure 34.18 for a fumed silica. The interpretations are the same as for the silica gel. 

Figure 15 illustrates the basic steps in the FT-deconvolution procedure, and what will occur if the peak to be sharpened is identical in all respects to the deconvolution peak. One obtains a single point located at the peak potential of the original peak. In real situations, this ultimmate sharpening is impossible for a variety of reasons, including noise on the data arrays. These problems will not be discussed. What is important is vi iat can be achieved. 

Many authors have shown the good agreement between (Si/Al)iv calculated from chemical compositions and from 29Si NMR spectra data (Thompson 1984 Diddams et al. 1984 Sanz and Serratosa 1984). (Si/Al)iv ratios were determined using the above formula and deconvoluted peaks for the five samples thus analysed. The (Si/Aliv) ratio is 9.2,8.8,5.1,4.7, and 6.1 for samples El (Li+), E2 (Na+), E3 (K+), E4 (NH4+), and E5 ((C2H5))4N+), respecUvely (Table 10-5). 

FIGURE 17 Raman vibrational spectrum of liquid water at temperature of 24°C and pressure of 128 bar. (From Carey and Korenowski, 1998.) The figure shows also the Gaussian deconvoluted peaks. 

Using sweep voltammetry Conway et found at the beginning of oxygen deposition on polycrystalline Pt in very pure 0.5 M H2SO4 three adsorption peaks followed by a flat minimum (see Figure 5). From charge ratios under the deconvoluted peaks, these workers concluded that these peaks represent OH adsorption in various apparent structural configurations e.g., for the (100) plane ... 

Figure 4.70. shows schematic TG DTG curves of a polymer with non-freezing water (curve 1) and a polymer with free and non-freezing water (curve II). The amount of each water fraction can be calculated from the area of each deconvoluted peak. The mass of water calculated from the vaporization method contains errors of several per cent in the repeatability, which are mainly due to setting the sample in the TG sample... 

Figure 10.3 X-ray photoelectron spectroscopy of TiN (3 min) in contact with bacteria for 3 s (a) time = 0 min and (h) time 120 min, showing the shift in deconvoluted peaks after bacterial inactivation.

Some of the interferences listed may be resolved automatically by allowing the spectrum analysis program to deconvolute peaks others may need correction by other means. For example, while deconvolution of the 242.00 keV peak of Pb and the 238.63 keV of Zpb may give satisfactory results for both peaks, it is by no means certain that including the 240.99 keV peak of Ra will provide acceptable values for all three peaks. 

N before and after annealing at 600°C (23.2 at % N) [90], (b) Raman spectra from the 1100 to 1800-cm region of amorphous carbon nitride film. The deconvoluted peaks have been assigned to D, G, and N bands depending on the nitrogen incorporation (a) 0 at % (b) 25.2 at %, (c) 33.2 at %, and (d) 23.2 at % in the films [90]. (c) D/G peak area ratio as a function of nitrogen concentration in the film [90]. (Reproduced from Thin Solid Films, 332 Chowdhury, A. K. M. S., et al., Vibrational properties of carbon nitride films by Raman spectroscopy, pp. 62-68. Copyright 1998, with permission from Elsevier Science.)... 

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