Anomalous peak widths

An alternative is to measure the FWHM of each peak as it is located and use that value to define the peak limits. That steps around the problem of anomalous peak widths... 

A third example can be taken from analytical chemistry. Absorption and resonance Raman spectra of phenol blue were measured in liquid and supercritical solvents to determine the solvent dependence of absorption bandwidth and spectral shifts. Good correlation between absorption peak shift and resonance Raman bands and between Raman bands and bandwidth of C-N stretching mode were observed while anomalous solvent effect on the absorption bandwidth occnrred in liquid solvents. Large band-widths of absorption and resonance Raman spectra were seen in supercritical solvents as compared to liquid solvents. This was dne to the small refractive indices of the supercritical solvents. The large refractive index of the liqnid solvents only make the absorption peak shifts withont broadening the absorption spectra (Yamaguchi et al., 1997). 

Even though the Ca is there it does not poison acetate formation, which appears to occur with a similar adsorption probability, but it does stabilise it towards decomposition. In fact the desorption at 455K, occurring in the presence of Ca, is what is known as a surface explosion [8], an autocatalytic decomposition, showing a very narrow half-width for the peak and anomalous desorption kinetics. 

Figure 7.6 FWHM of full energy, single escape, double escape and annihilation peaks as a function of energy, demonstrating the anomalous width of single escape and annihilation peaks (the detector used had a FWHM at 1332.5 keV of 1.88 keV)...

The dynamic resistance dU/dl(U) and its derivative d2U/dF(U) were measured with the point contact technique at 1.7 K on Tmo.gsSe and at 1.8 K on TmosySe. While dU/dl does not show any anomalous structure for Tmo eySe (with trivalent Tm), a strong resistance peak with a characteristic width of 2.3meV is observed for Tmo.geSe. This suggests a hybridization gap (see p. 363) for the spectra, see the paper, Frankowski, Wachter [15,16], Wachter [17] for Tmo.eySe, also see Frankowski, Wachter [18] for the effect of magnetic fields, see p. 373. 

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