E) 2 Styryl substituted 6,7 difluoroquinolines and quinoxalines were synthesized by the condensation of the corresponding 2 methylbenzazines with aromatic aldehydes. Photolumines cence of the synthesized 6,7 difluoro 2 styrylbenzazines was studied.
The analysis conditions required to make a quantitative determination of ten oxygenates in different commercial gasolines are determined using a Kristall 5000.2 chromatograph manufactured by the Special Design Office Khromatek JSC.The method most often used to quantitatively determine oxygenates in commercial grades of gasoline is capillary gas chromatography with low-temperature thermostatting (GOST R52714, ASTM D 6729, ASTM D 6730, and ASTM D6733). Alcohols and esters are the main oxygen-bearing compounds used as anti-knocking additives and dopes in commercial automotive gasolines, and they are not determined with a sufficient degree of reliability by the methods just mentioned. In particular, the peaks of methanol and ethanol become indistinct at low temperatures and may be lost altogether at low concentrations. These peaks may also overlap with the peaks of other components of gasoline.Another shortcoming of the above-indicated methods is that they do not conform to European standard EN 228, which governs the testing of automotive gasolines. EN 228 requires that the methods described by the standards EN 1601 and EN 13132 be used to determine oxygenates. The first method is based on the use of a methanator in which oxygen-bearing compounds are converted to methane. The concentration of methane is determined by a flame-ionization detector. This method is almost never used in Russia, due to the unreliable performance of the methanator. The method described in EN 13132 has been extended to unethylated gasolines having a final boiling point no higher than 220°C. This method was developed to determine the contents of individual organic oxygen-bearing compounds within the range from 0.17 to 15% for cases in which the total content of organically
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