Glycerol, absorption spectrum

Figure 2.11. The dependence of the position of the fluorescence spectrum maximum on excitation wavelength for tryptophan in a model medium (glycerol) at different temperatures (a) and singletryptophan proteins (b). 1, Whiting parvalbumin, pH 6.S in the presence of Ca2+ ions 2, ribonuclease Th pH 6.5 3, ribonuclease C2, pH 6.5 4, human serum albumin, pH 7.0, +10"4 M sodium dodecyl sulfate 5, human serum albumin, pH 3.2 6, melittin, pH 7.5, +0.15 M NaCl 7, protease inhibitor IT-AJ from Actinomyces janthinus, pH 2.9 8, human serum albumin, pH 7.0 9, -casein, pH 7.5 10, protease inhibitor IT-AJ, pH 7.0 11, basic myelin protein, pH 7.0 12, melittin in water. The dashed line is the absorption spectrum of tryptophan.

Absorption spectra of peridinin in different solvents are shown in Fig. 2a. In the nonpolar solvent M-hexane, the absorption spectrum exhibits the well-resolved structure of vibrational bands of the strongly allowed S0-S2 transition with the 0-0 peak located at 485 nm. In polar solvents, however, the vibrational structure is lost and the absorption band is significantly wider. In addition, there are also differences between the various polar solvents. Although the loss of vibrational structure is obvious, a hint of shoulder is still preserved in methanol and acetonitrile, but in ethylene glycol and glycerol the absorption spectrum is completely structureless with a broad red tail extending beyond 600 nm. 

Fig, 4, UV-visible absorption, MCD, and EPR spectra of the glycerol-inhibited Mo(V) form of DMSO reductase from R. sphaeroid.es. Upper panel (---) room temperature absorption spectrum of the native Mo(VI) form (—) glycerol-inhibited Mo(V) form. Lower panel MCD spectra of the glycerol-inhibited Mo(V) form at a magnetic field of 4.5 T at 1.61, 4.22, 9,6, and 27,2 K, showing that all bands increase in intensity with decreasing temperature. Inset shows the X-band EPR spectrum of the MCD sample recorded at 150 K, Reproduced with permission from Finnegan et al. (85). 

Leaflets from ale, mp 106 . Salty taste. bp74t 146. Strong base pKs — 4.19, absorbs water and C02 from air- Absorption spectrum Purvis. J. Chem. Soc. 103, 2286, 2293 (1913). Freely sol in water, glycerol, glycols one gram dissolves in 2 ml of 95% alcohol. Insol in ether. pH of a 10% aq so In 10.8-11.8. Forms a so] compd with theophylline. Keep tightly closed and protect from light. 

Figure 2 Absorption spectrum in water upper curve) and variations in quantum yields of Co2+ lower curves) with excitation energy and solvent medium on irradiation of [Co(NH3)6Br]2+. Aqueous solvent media employed H20, 80% MeCN, A 50% glycerol, A 75% glycerol, 87% HdP04, (Reproduced by permission from J. Amer. Chem. Soc1975, 97, 219)...

Figure 9. Absorption spectrum of polymeric sulfur in glycerol...

Fig. 3.1 Curve 1 absolute intensity (except for an arbitrary constant) of the phosphorescent emission of crystal violet in glycerol at 178 K, showing the alpha and beta bands. Curve 2 similar absolute intensity of fluorescent emission (plus 5-10 % phosphorescence), at 178 K. Curve 3 for reference, the absorption spectrum. Curve 4 intensity of green phosphorescence band (not corrected for plate characteristics). Reprinted with permission from [3]. Copyright 1942, American Chemical Society...

Figure 10 Spectral diffusion broadening as a function of waiting time fwfor different ageing times. The sample is protoporphyrin IX in a dimethylformamide/glycerol glass temperature is 100 mK. Insert Broad-band absorption spectrum. The arrow marks the wavenumber where hole burning was performed.

The low-temperature absorption spectrum of dithionite-reduced glycerol-grown S. pombe cells or mitochondria (Figs. 3B, 4B) differs in... 

An ether extraction of nutmeg gives large quantities of trimyristin, a waxy crystalline solid of melting point 57 °C. The IR spectrum of trimyristin shows a very strong absorption at 1733 cm-1. Basic hydrolysis of trimyristin gives 1 equivalent of glycerol and 3 equivalents of myristic acid (tetradecanoic acid). 

Polarproticsolventswith hydrogen bonds,likewaterandalcohols.Thewavelength at the absorption maximum ofthe solvated electron spectrum lies in the visible domain, between 500 and 820 nm for instance, it is around 525 nm for glycerol and 640 nm for methanol. 

The application of low-temperature techniques to the investigation of protein spectra in the ultraviolet region was initiated by Lavin and Northrop (1935) who investigated the ultraviolet absorption spectra of pepsin, serum albumin, and ovalbumin in glycerol, and showed that the fine structure of the protein spectrum was enhanced at — 100°C. Preliminary reports of similar work have been published by Randall and Brown (1949) on thin films of sublimed tryptophan and phenylalanine at 90°C., and by Sinsheimer et al. (1949) for tryptophan at 77.6°K. Loof-bourow and his coworkers (Sinsheimer et al., 1950) have begun publication of a series of papers reporting much more comprehensive work on the influence of low temperature on the spectra of amino acids and proteins in thin films and in solid solution. Beaven et al. (1950) have reported a few results on thin Aims of the aromatic amino acids. 

Fig.l shows the absorption spectra of R.spaeroides Res at 1.7 K frozen in buffer-glycerol ( 0/60, v/v) solution (dashed) and in poly-vinylalcohol film (solid line). The second derivative of the former spectrum has two negative peaks at 900 and 910 nm reflecting the fine structure of the P band /ll/. No structure is revealed for PVA film. 

Analyze the infrared spectrum by identifying the principal absorption bands. Look for peaks in the spectrum that may indicate possible contamination from methanol, glycerol, or free fatty acids. Indicate any impurities found in your biodiesel bases on the infrared spectrum. 

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