Organic phase concentration

The CHI can be obtained without preliminary method development direcdy from a single fast-gradient run with a cycle time less than 15 min with a 150-mm column [40] or 5 min with 50-mm column [42]. In this case, the obtained retention time, tr, is expressed within an organic phase concentration (< o) scale using a calibration set of compounds. CHI value can be obtained from ... 

Valko, K., Siegel, P. New chromatographic hydrophobicity index ( /o) based on the slope and the intercept of the logk versus organic phase concentration plot. J. Chromatogr. 1993, 637,49-61. 

Concentration of metal in organic phase Concentration of metal in aqueous phase... 

FIGURE 7.17 Water organic-phase concentration versus acid organic concentration at the LOC conditions for TBP/ra-octane system equilibrated with different acidic aqueous phases. (Redrawn from R. Chiarizia and A. Briand, Solvent Extr. IonExch., 25 351-371, 2007.)... 

Fig. 1. Schematic drawing of the high-speed stirring (HSS) apparatus. The increase in the interfacial area by the stirring can increase the amount of the interfacial adsorbate, which results in the decrease in the organic phase concentration. The figure at the right is a schematic presentation of an observed result.

Propargyl methanesulfonate (0.35 mol) and benzaldehyde (0.44 mol) were dissolved in 148 g toluene and 28% NH4OH (2.96 mol) added at 24°C over 7.5 hours. Thereafter the mixture was stirred 15 hours, the organic phase concentrated, and the product isolated in 80% yield, bp = 80-83 °C at 2.5 mmHg (Note 3). 

FIGURE 23-12 Schematic illustration of variation in distribution ratio as a function of pH, concentration of extracting reagent HL in the organic phase, concentration of masking reagent A in the aqueous phase, and concentration of an adduct former B in the organic phase. A, pH variable B, [HL] variable C, [A] variable D, [B] variable. (Adty>ted from Schweitzer. )... 

Salt solutions As a first approximation dissolved salt will increase the distribntion coefficient (increase the organic phase concentration relative to the water concentration). For details on calculating the scale of the effect, refer to ref 10. 

A third reason for feeding some of the monomer to downstream reactors is to build the solids level of the product. This increase in solids can occur without the flocculation and rheology problems that might exist if the organic phase concentration were high in the early reactors. 

FIGURE 8.4-5 Measured and calculated organic-phase concentrations of nitric acid (X) and umaium (o) during coexiraciion by TBP in a Lewis cell. Concentrations are expressed as a percentage of their equilibrium values. From Ref. 28. with permission. 

To illustrate which components are necessary to prepare an ISE membrane, let us again go back to a simple extraction experiment as it was similarly described in Section 3.1.1. Consider an aqueous potassium chloride solution equilibrated with an immiscible organic phase containing an electrically neutral ionophore for K+, that is, a receptor compound that binds the potassium ion selectively. How does the phase boundary potential between these two phases depend on the KCl concentration in the aqueous phase Upon equilibration of the two phases, some KCl will be present in the organic phase (Figure 5). For low amounts of KCl in the system, the potassium ions in the organic phase will be present in the form of ionophore complexes, and there will be an excess of free ionophore, L. In comparison to the concentration of the ionophore complex, the organic phase concentration [K+] of free potassium ions that are not bound by the ionophore is very low and can be calculated from the formation constant, of the potassium ion complex, [LK+] ... 

The extraction rate of Ni(pan)2 into toluene is known to be very slow even under an HSS condition, whereas the addition of PADA even at the diluted concentration of 10 M could accelerate the extraction rate about ten times. At this time, only Ni(pan)2 was extracted without any consumption in PADA after the extraction, except a significant decrease in the organic phase concentration of PADA during the stirring, as shown in Figure 2.28. Analyses of the experimental results suggested the interfacial adsorption of Ni(pada) + complex, which was rapidly formed in the... 

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