Petroleum fluorescence spectra

A variety of industrial processes benefit from the use of NIR-Raman spectroscopy. In a study examining unleaded petroleum gasoline, with excitation at 514 nm from an argon laseg no Raman features were observed above the strong fluorescence. With He/Ne laser excitation at 633 nm, several Raman features appeared above the background. With excitation at 785 or 852 nm, a good quality Raman spectrum was obtained. In the textile industry, NIR-Raman was used to examine ready-made textiles for the discrimination of the different raw materials. 

The most suitable adsorptive materials were precipitated calcium carbonate, inulin, or sucrose (powdered). If the petroleum ether chlorophyll solution was then shaken with the adsorptive material, the latter carried down the pigment, and with a certain excess of this, only the carotene remained in solution, escaping adsorption. In this way a green precipitate and a pure yellow, fluorescence-free carotene solution were obtained (test for fluorescence in my luminoscope [Zeitschrift fur physikcdische Chemie (1901) 36, S. 450 Diese Berichte (1906) 24, S. 234]). This carotene solution showed a spectrum with absorption bands at 492-475 and 460-445 nm. If it was shaken with 80 % alcohol, the lower alcohol-water phase remained completely colorless. 

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