Wavelength Tables

A number of wavelength tables with spectral descriptions and relative line intensities are available to the analytical spectroscopist. The most complete and most widely used tables are the MIT Wavelength Tables, which include about 110,000 wavelengths for 87 elements from 2000 to 10,000 A. Spectral line intensities are estimated from 1 to 9000, for excitation in a dc arc and a high-voltage ac spark. The atom lines are designated with the Roman numeral I and the singly ionized lines by the Roman numeral II. 

Several other tables are available that are condensations of the MIT table. Earlier editions of Lange s Handbook of Chemistry, have a table of lines from 2000 to 9200 A by wavelength and another of sensitive lines by element. Shorter lists of 500 sensitive lines for 85 elements arranged by wavelength and also by element have been prepared from the longer MIT tables by Harrison.  

Other tables based on the MIT compilation are given by Erode (see footnote 2), Harrison, Lord, and Loofbourow, and Ahrens and Taylor. Ahrens and Taylor also identify possible interfering spectral lines in their table. 

An extensive study of spectral line intensities has been made at the National Bureau of Standards by Meggers, Corliss, and Scribner. They used copper electrodes and a dc arc to obtain their data on 70 elements. About 39,000 wavelengths are listed. Tables are available by wavelength and also by element. The data are included in the following four monographs available from the U. S. Superintendent of Documents  

NBS Monograph 53, Experimental Transition Probabilities of Spectral Lines of Seventy Elements (1962). 

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The total anthocyanin content can often be determined in crude extracts containing other phenolic materials by measuring absorptivity of the solution at a single wavelength (Table 6.3.1). This is possible because anthocyanins have typical absorption bands in the 490 to 550 nm region of the visible spectra — far from the absorption bands of other phenolics with spectral maxima in the UV range. ... 

Harrison, G. R. 1939, MIT Wavelength Tables, New York John Wiley Sons. 

Previous experience in arc and spark emission spectroscopy has revealed numerous spectral overlap problems. Wavelength tables exist that tabulate spectral emission lines and relative intensities for the purpose of facilitating wavelength selection. Although the spectral interference information available from arc and spark spectroscopy is extremely useful, the information is not sufficient to avoid all ICP spectral interferences. ICP spectra differ from arc and spark emission spectra because the line intensities are not directly comparable. As of yet, there is no atlas of ICP emission line intensity data, that would facilitate line selection based upon element concentrations, intensity ratios and spectral band pass. This is indeed unfortunate because the ICP instrumentation is now capable of precise and easily duplicated intensity measurements. 

ICP Emission Spectrometry—Optima 3000 Wavelength Tables, operating manual, Vol. 3, The Perkin-Elmer Corporation, 1993, p. 52. 

The relative quantum yields of the two processes depend on the irradiation wavelength (Table 4.2). 

The particle diameter D is related to the full width at half maximum A by the Debye-Scherrer equation D = 0.9 XIA cos0, where 20 is the diffraction angle and X is the X-ray wavelength. Table 27.1 lists the particle size and lattice plane spacing calculated using the strongest (h,k,l) peak for the Fe, W, Mo carbides, nitrides, oxynitrides and oxycarbides. It is important to note that the calculated particle size using the Debye-... 

G.H. Dieke The Hydrogen Molecule Wavelength Tables (Wiley-Interscience, New York 1972)... 

As expected, ethylene and acetone are formed in equal amounts in the photolysis of 2-pentanone . The primary quantum yield, n, is practically independent of temperature and of 2-pentanone pressure, but increases with decreasing wavelength (Table 21). 

The photolysis or pyrolysis of diazoesters is the only source of carboalkoxy-carbenes and although numerous examples can be found in the literature concerning the reactivity of these carbenes, very little information is available on the kinetics of the decomposition. The photolysis of methyldiazoacetate yields carbo-methoxycarbene which adds stereospecifically to 2-butene. The quantum yield of the photolysis of ethyldiazoacetate has been determined in various solvents at different wavelengths (Table 12) . Thermal decomposition occurs above 150 °C although the presence of catalysts greatly accelerate the decomposition . Carboalkoxycarbenes are very selective with respect to insertion reactions, due to... 

Bortolus and Monti have determined the quantum yields of azobenzene isomerization in different solvents.They found an increase of E Z isomerization but a decrease of Z E isomerization when solvents with high dielectric constant are used. This phenomenon is independent of the irradiation wavelength. Table 1.2 shows the special feature of wavelength-dependent quantum yields of azobenzene. 

Choice of X-ray radiation copper Ka is the most popular radiation source used in diffractometry because of its short wavelength. Table 2.4 lists the detection limitations of X-ray radiations commonly used in diffractometry and... 

On this basis, Siegbahn and his associates made very accurate measurements of wavelength in relative (kX) units and these measurements form the basis of most published wavelength tables. 

The present situation is not entirely clear, but the wavelength tables published in 1974 by the International Union of Crystallography [Vol. 4, G.ll], which are reproduced in Appendix 7, are based on Eq. (3-9). 

In 1963, Ryskin et al. 16), working at 4.2 °K, found that the absorption band of the visible divides into two bands, the more intense, a being located at the longest wavelengths (Table 9). 

The fluorescence spectra for the creosote (a) and the sediment extract from Station S5 (b) are very similar, while the extract from station S8 has no emission at lower wavelengths (Table I). 

Until recently, the use of anomalous scattering had been restricted to those proteins which contained iron or heavy atom derivatives for which anomalous scattering was appreciable at CuK, wavelengths (Table 1). Synchrotron radiation provides a tuneable source of X-rays so that the wavelength may be varied to optimise anomalous scattering for the particular atom present in the crystal (section 3(d)). 

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