Component Fractions

Nrnnber Components Fraction (K) E/R R Phase E Phase tions... 

Comparative Evaluation of Related Compounds. Structural studies are incomplete, but NMR and gas chromatographic - mass spectroscopic analysis of a component (fraction 7) isolated by HPLC indicated biphenyl characteristics (30). In an attempt to evaluate the cytolytic effect of compounds with similar structure, 4-hydroxybiphenol and 2-hydroxybiphenol were tested for lytic effects on P. brevis. Bioassays of 2- and 4-hydroxybiphenol indicated that both compounds were cytolytic to P. brevis (31). 

Fig. 3.121. Structures of the isolated quinoline yellow components. Fraction 4, = S03Na,...

Three primary tests are incorporated in the health effects area. The microbial mutagenesis assay is based on the property of selected Salmonella typhimurium mutants to revert from a histidine requiring state to prototrophy due to exposre to various classes of mutagens. The test can detect nanogram quantities of mutagens and has been adapted to mimic some mammalian metabolic processes by the addition of a mammalian liver microsomal fraction. The test is used as a primary screen to determine the mutagenic activity of complex mixtures or component fractions. 

Eosinophils -mblood [AUTOMATED INSTRUMENTATION - HEMATOLOGY] (Vol 3) -blood components [FRACTIONATION,BLOOD - CELLSEPARATION] (Vol 11)... 

Component fraction (300 psia) Yil Kvsi (350 psia) Yi/Kysi... 

Distillation was the first method by which petroleum was refined, but this was not so much a refining method as a method for separation of the crude oil into fractions, such as kerosene, for which there was a demand and hence a ready market. Nevertheless, as petroleum refineries have evolved into present-day complexes, distillation units may still find a place, depending upon the characteristics of the crude oil feedstock, in a refinery sequence. A multitude of separations is accomplished by distillation, but its most important and primary function in the refinery is its use for the separation of crude oil into component fractions (Table 7-2) (Speight, 1999). 

A general advantage of fractionation is that it breaks up broad particle populations into component fractions, making it possible to look at the components individually and to examine their role within and contribution to the overall population. Furthermore, each fraction typically contains a sufficient number (10° - 10iU) of particles for valid statistical representation. 

Blended component fractions are computed for the heavy naphtha cut from the base mix. 

A short-path distillation procedure may be used in situations where a simple distillation is required, as purification from non-volatile components/fractional distillation with a Kugelrohr apparatus is difficult. A water-jacketed, semi-micro distillation apparatus is illustrated in Figure 1.7. Heating can either be achieved with the aid of an oil-bath, an isomantle, or a flame (Caution ensure that there are no flammable solvents nearby). For larger scale distillations, a round-bottomed flask should be attached to a distillation column, a still-head, and condenser. The column used in the distillation is variable, and may be either a Vigreux column or a column packed with glass helices. 

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