Bar graph spectrum

The principle of ID-MS is depicted in Figure 7.11, a bar graph spectrum of the sample, which has two isotopes, to which a known amount of spike, the enriched lighter isotope, was added. The measured isotope ratio, R, is given by... 

Figure 2.227 Evaluation of isotope patterns from an MID analysis of hexachlorobiphenyl by comparison of relative Intensities (shown as a bar-graph spectrum).

Modern mass spectrometers are interfaced with computerized data handling sys terns capable of displaying the mass spectrum according to a number of different for mats Bar graphs on which relative intensity is plotted versus m z are the most common Figure 13 40 shows the mass spectrum of benzene m bar graph form... 

The mass spectrum of a compound is typically presented as a bar graph with masses (m/z values) on the x axis and intensity, or relative abundance of ions of a given m/z striking the detector, on the y axis. The tallest peak, assigned an intensity of 100%, is called the base peak, and the peak that corresponds to the unfragmented cation radical is called the parent peak or the molecular ion (M+). Figure 12.2 shows the mass spectrum of propane. 

Mass spectrum of neon (a) actual appearance, (b) bar graph representation. 

C02-0012. Figure 2-17 gives the isotopic composition of naturaiiy occurring chromium (Cr). Draw a bar graph that shows the mass spectrum of Cr. 

Fig. 5.14 Experimental (a, black curve), fitted (a, red) and simulated (b) NIS spectrum of the Fe (Ill)-azide complex obtained at the BP86ATZVP level (J = 20 K). Bar graphs represent the corresponding intensities of the individual vibrational transitions. The blue curve represents the fitted spectrum with a background line removed (taken from [63])...

As already stated, the mass spectrum is a two-dimensional graph that reports the m/z ratio of ions (abscissa) and their relative intensity (ordinate). The most abundant ions are assigned as 100%. A mass spectrum can be displayed as peak profiles or as bar graphs corresponding to the peak centroids, i.e. the weighted centre of mass of the peak, or as a table (Figure 2.16). The most abundant ions in a mass spectrum constitute the base peak whose intensity is assumed equal to 100%. 

Figure 2.16 Different ways to represent a mass spectrum peak profile (a), bar graph (b) and table (c)...

Fig. 1.3. Three representations of the molecular ion signal in the field desorption mass spectrum (Chap. 8) of tetrapentacontane, C54H110 (a) profile spectrum, (b) bar graph representation, and (c) tabular listing.

Bar graph representations are much better suited for visualization of isotopic compositions than tables, and in fact they exactly show how such a distribution would appear in a mass spectrum (Fig. 3.1). This appearance gives rise to the term isotopic pattern. 

Figure 22-9 Hlgh-resolution double-focusing sector-field mass spectrum distinguishing 31P, , 5N 60+.and l4Nl6OH with a resolution of ml Am = 4 000. The spectrum is a bar graph of detector counts/s at each increment of m/z. [From J. S. Becker,...

FIGURE 1.22 Effect of site geometry on the pre-edge of Fe(III) complexes.51 Below each spectrum the bar graphs indicate the contribution to the intensity from electric dipole and quadrupole mechanisms for each final state. 

The mass spectrum is a report of the relative numbers or abundances of ions of each mlz that are detected, and it is often presented in the form of a bar graph. The most abundant ion, the base ion, is assigned a value of 100, and the amounts of the other ions are expressed as percentages of this. A mass spectrum for benzene is shown in... 

The mass spectrometer usually plots the spectrum as a graph on a computer screen. This information is tabulated, and the spectrum is printed as a bar graph or as a table of relative abundances (Figure 12-16). In the printed mass spectrum, all the masses are... 

Mass spectrum of 2,4-dimethylpentane, given both as a bar graph and in tabular form. Abundances are given as percentages of the strongest peak (the base peak). In this example, the base peak is at m/z 41 and the molecular ion peak (parent peak) is at m/z 100. Notice that the molecular ion has an even mass number, while most of the fragments are odd. 

The same spectrum displayed on top as a profile of ion abundances and below as a bar graph of the centroids of the peaks. 

Figure 58. Ca-HCl action spectrum, monitoring CaCl - fluorescence ( 620nm), while scanning the pump laser in the vicinity of the Ca line. The bar graphs indicate the calculated areas of the corresponding absorption features (see text for details).

The mass spectrum of triamcinolone acetonide was obtained from Squibb House Standard 45885-008 by direct insertion of a sample into an MS-9 double focusing mass spectrometer. Intensities were measured from the low resolution mass spectrum. Results are summarized as a bar graph (Fig. 3). The high resolution mass spec-... 

Fig. 2. Excitation profiles of the v, Raman lines of all-tra s-(3-carotene for the (a) isopentane solution at 160 K, (b) spin-coated film at 11 K, and (c) randomly oriented crystals (grain size < I mm) at 11 K (bar graphs) as well as their optical absorption spectra (broken lines). The optical absorption spectrum in (c) is taken from that of microcrystals dispersed in a KBr disk.

The mass spectrum of pentane, shown as a bar graph and in tabular form. The base peak represents the fragment that appears in greatest abundance. The m/z value of the molecular ion gives the molecular mass of the compound. 

---