Hydrophobic Fraction

However, the use of a HPLC separation step enabled a remarkable acceleration of the deconvolution process. Instead of preparing all of the sublibraries, the c(Arg-Lys-O-Pro-O-P-Ala) library was fractionated on a semipreparative HPLC column and three fractions as shown in Fig. 3-2 were collected and subjected to amino acid analysis. According to the analysis, the least hydrophobic fraction, which eluted first, did not contain peptides that included valine, methionine, isoleucine, leucine, tyrosine, and phenylalanine residues and also did not exhibit any separation ability for the tested racemic amino acid derivatives (Table 3-1). 

Miner. Process Extra. Metall. Rev., 11 187-210 Yarar, B., Haydon, B. C., Kitchener, J. A., 1969. Electrochemistry of the galena-diethyldithio carbamate-oxygen flotation system. Trans. Instn. Min. Metall. Sec.C, 78 C181 - C184 Yekeler Meftuni, Sonmez Ibrahim, 1997. Effect of the hydrophobic fraction and particle size in the collectorless column flotation kinetics. Colloids and Surfaces A Physicochemical and Engineering, 121(1) 9-13... 

Fig. n. 5 Adsorption of DOC from a podsol by goethite and desorption after 24 hr of the hydrophilic and hydrophobic fraction by different solutions. Soil solution was a DOC-free solution of similar inorganic composition as the DOC used for adsorption (Kaiser Zech, 1999 with permission). 

The results show that RPC will also separate low molar mass lignosulfonates into hydrophilic and hydrophobic fractions as well as into a far greater number of individual components than obtained by fractionation with GPC. 

Fraction I, which is less hydrophobic than fractions III and V (Fig. 8), contains lower molar mass compounds than fraction III, which in turn contains lower molar mass compounds than the most hydrophobic fraction (fraction IV). 

Fraction I, which consists mainly of low molar mass compounds, also contains a small amount of high molar mass lignin derivatives eluting with relative retention volumes of 0-0.1. These derivatives are polar and some may be bound to carbohydrates, or otherwise they would have been eluted by RPC along with the hydrophobic fractions II-IV. 

High-surface-area polymers can be used to accumulate large amounts of relatively insoluble organic compounds from very large volumes of water. In the adsorption step of the accumulation, the more soluble components are not recovered efficiently so that the accumulated solutes do not accurately reflect the proportions of different compounds present at trace levels in the water. Nevertheless, the very simple polymer approach can be used for many studies because the mutagenicity appears to reside in the hydrophobic fraction that the polymers accumulate efficiently. This conclusion is based on favorable bioassay comparison of the extracts accumulated by the XAD-2 method and the extracts collected by the more complicated and expensive freeze concentration method (216, 233). 

B. Cosovic and V. Vojvodic, Adsorption behaviour of the hydrophobic fraction of organic matter in natural waters, Marine Chem. 28(1989) 183-198. 

Polubesova, T., Chen, Y., Navon, R., and Chefetz, B. (2008). Interactions of hydrophobic fractions of dissolved organic matter with Fe3+- and Cu2+-montmorillonite. Environ. Sci. Technol. 42,4797 1803. 

Physical-chemical separation (hydrophilic/hydrophobic fractions)... 

Dilling, J., and Kaiser, K. (2002). Estimation of the hydrophobic fraction of dissolved organic matter in water samples using UV photometry. Water Res. 36,5037-5044. 

Sulfur K-edge NEXAFS also detected significant differences between oxidation states in hydrophobic and hydrophilic organic matter (Hundal et al., 2000). Oxidized organic sulfur forms were dominant in the hydrophilic fraction, whereas reduced sulfur forms were dominant in the hydrophobic fraction. 

DOM Sources Hydrophobic Fractions Total Hydrophobic Fractions Total HiA HiB HiN HoA HoB HoN... 

Several comprehensive systems have been developed for the MD-LC fractionation of protein mixtures. Strong cation-exchange or SEC has been coupled with RP-LC to fractionate proteins based on charge or size and then on hydrophobicity. Fractions from the RP column were analyzed by UV detection and MS. 

Schafer et al. [35] studied the role of concentration polarization and solution chemistry on the morphology of the humic acid fouling layer. Irreversible fouling occurred with all membranes at high calcium concentrations. Interestingly, it was found that the hydrophobic fraction of the humic acids was deposited preferentially on the membrane surface. This result is similar to the work of Ridgway et al. [31], who showed that the hydrophobic interaction between a bacterial cell surface and a membrane surface plays a key role in biofilm formation. The formation of two layers, one on top of the other, was also observed by Khatib et al. [36]. The formation of a Fe-Si gel layer directly on the membrane surface was mainly responsible for the fouhng. 

The first is flotation. This is a metal ore beneficiation technique based on separating suspended particles on the basis of, intrinsic or intentionally achieved, differences in hydrophobicily. When air bubbles cU e blown through such a system these bubbles attract the more hydrophobic components, subsequently moving them upward. In practice, surfactants are also present so that a foam collar appears on the liquid, from which the hydrophobic fraction can be collected. 

These examples allow us to describe tiie structure of surfactant aggregates in terms of the value of the surfactant parameter. Indeed, this is the case for simple closed surfaces, where the interior contains the hydrophobic fraction (v/al[Pg.145]

Cells grown under autotrophic growth condition (in BM) were disrupted by sonication for 1 min five times, and the hydrophobic fraction was extracted with pure redistilled chloroform. Acetone insoluble fraction of chloroform extracts was analyzed by TOF-MS (KOMPACT MALDl 11, Shimadzu, Kyoto, Japan) and its methanolysate was analyzed by GC/MS(E1) (JMS-DX303, JEOL, Tokyo, Japan). Acetone soluble fraction was directly analyzed by GC/MS(E1). HD-1 cell extract was prepared as follows autotrophically grown cells were centrifuged, washed, freeze-dried and weighed. 

When the hydrophobic fraction was analyzed by silica 60 TLC, quite apolar substances were found at the front of the developing solvent (chloroform/methanol/watep=65 25 4). Therefore, we examined whether or not the strain HD-1 produced hydrocarbons from C02. HD-1 cells were collected from 10 liter BM culture. Non-polar substances contained in the chloroform extracts of the disrupted cells were directly analyzed by GC/MS(E1) (Fig. 3a). The characteristic fragmentation patterns and each mass number of the molecular ion peak of these... 

---