Recovered fraction

Figure 1.1 illustrates the diversity of products derived from petroleum classified according to their distillation ranges and number of carbon atoms. From one crude to another, the proportions of the recovered fractions vary widely. A good illustration is the gasoline fraction (one of the most economically attractive) a crude from Qatar gives about 37 per cent by volume whereas a Boscan crude oil only yields 4.5%. 

This polypeptide was purified by gradient elution RP-HPLC [Waters 600/486 HPLC system TSK-ODS-120 T column (300 x 21.5mm i.d., Tosoh Corp. Yamaguchi, Japan) 10 pm octadecylsilica eluent A 0.1% TFA/H,0 and B 0.09% TFA in 60% MeCN/H20, linear gradient of 0-100% B over 90 min UV detection (254 nm) flow rate 6.0mL-min-1]. The crude synthetic and purified 110-mer polypeptide, which was obtained from the recovered fractions, was analyzed by analytical RP-HPLC [column as above (150 x 4.6 mm i.d. 5 pm octadecylsilica eluent linear gradient 0-100% B over 60min UV detection (214nm) flow rate lmL-min-1]. b Adapted from Keah and Hearn)14 with permission. 

Finally, when RPC methods are used in preparative studies with peptides, the opportunity routinely exists for subsequent analysis of the recovered fractions by a variety of analytical methods including high-speed RP-HPLC, HP-IEX, HP-HILIC, or HP-IMAC, zonal or micellar electrokinetic high-performance capillary electrophoresis (HP-CZE and MECK-CZE), capillary electrochromatography (CEC), or capillary isotachophoresis. The combination of the RPC information, drawn from the In k versus i > plots, with the data derived from on-line spectroscopic detection thus readily provides a comprehensive opportunity to assess the purity of an isolated peptide, many of the physicochemical features of the interaction, as well as a means to optimize the resolution in the RPC separation. 

Battery type Materials recovered Fraction of cells recycled Economic advantages... 

The apparent discrepancy between the yield of recovered fractions and the amount of starting sample is explained by the difference in solids determination. The solids in the combined starting sample were determined by oven-drying the individual samples. The yields of the individual... 

To check the recovered fractions, we equilibrated the HPLC with 60% acetonitrile. The standard, XX, and the first cartridge eluant were run under these conditions (Fig. 12.2b).The first cut chromatogram was examined for the presence of a peak with the same retention time as the standard. The remaining SFE elution fractions were each run at the same conditions and examined for peaks eluting with the standards retention times (Fig. 12.2, c and d). 

Based on this evidence further analysis of the three recovered fractions was not necessary to shed any further light on the sample recovery process. However, this... 

Fig. 8.7. Overlaid analytical chromatograms from the preparative liquid fraction 2 and the recovered fraction...

Isolation of Metabolites from Poultry Bile for Spectral Identification. Pooled samples of bile from poultry receiving feed medicated at 25 ppm semduramicin sodium for 7 days were extracted with ethyl acetate followed by chloroform. Abundant metabolites were isolated by collection of fractions from repeated injections on a normal phase silica HPLC column. The recovered fractions were analyzed by Fast Atom Bombardment Mass Spectrometry and proton NMR spectroscopy. 

For extractions repeated n times with fresh portions of the organic phase at constant Vaq and Torg. the total recovered fraction E is defined as... 

The total mass of all the recovered fractions must equal at least 97 % of the sample charged. If this recovery is not obtained, repeat the test. 

If 6 is the fraction of adsorbed sites, Fq the volume of the adsorbed phase, and 1-9 the recovered fraction, the voluminal speed of this elementary step can be written as (defects being diluted) ... 

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