Pseudo-ions

The sample is disrupted completely and distributed over the surface as a function of interactions with the support, the bonded phase, and the tissue matrix components themselves. The solid support acts as an abrasive that promotes sample disruption, whereas the bonded phase acts as a lipophilic, bound solvent that assists in sample disruption and lysis of cell membranes. The MSPD process disrupts cell membranes through solubilization of the component phospholipids and cholesterol into the Cis polymer matrix, with more polar substituents directed outward, perhaps forming a hydrophilic outer surface on the bead. Thus, the process could be viewed as essentially turning the cells inside out and forming an inverted membrane with the polymer bound to the solid support. This process would create a pseudo-ion exchange-reversed-phase for the separation of added components. Therefore, the Cis polymer would be modified by cell membrane phospholipids, interstitial fluid components, intracellular components and cholesterol, and would possess elution properties that would be dependent on the tissue used, the ratio of Cis to tissue employed and the elution profile performed (99-104). 

Ion-interaction chromatography is an intermediate between reversed-phase and ion-exchange chromatography. Introduction of amphiphilic and Uo-philic ions into the mobile phase causes their adsorption on the hydrophobic surface of packing material with subsequent transformation into a pseudo ion-exchange surface. Ionic interactions with charged analytes can occur in the mobile phase and with counterions that may be adsorbed on the stationary-phase surface. 

So far we have summarized different ways to present salinity. Strictly speaking, the effect of an ion may be different from the effect of any other one, so we should take into account every ion separately. We have to use a kind of pseudo-ion concept, however, to present salinity because (1) we do not fully understand the effect of each ion, (2) it is difficult and tedious to present the effects of so many ions and their reactions, and (3) the effect of an ion could be different in different processes. 

In this example, the injection water compositions were shown in Table 10.8. To simplify UTCHEM simulation, we combine some ions into "pseudo-ions" Na -i-K" to Na", Ca -I-Mg " to Ca, and COs -tHCOs" to Table 10.13... 

In principle, surface atomic and electronic structures are both available from self-consistent calculations of the electronic energy and surface potential. Until recently, however, such calculations were rather unrealistic, being based on a one-dimensional model using a square well crystal potential, with a semi-infinite lattice of pseudo-ions added by first-order perturbation theory. This treatment could not adequately describe dangling bond surface bands. Fortunately, the situation has improved enormously as the result of an approach due to Appelbaum and Hamann (see ref. 70 and references cited therein), which is based on the following concepts. 

Ultramicrons formed from globulin salts are doubtless charged by the adsorption of ions in a manner similar to that just indicated. It is interesting that the charged ultramicrons have a greater mobility under the influence of a potential fall than the ordinary proteid ion. Hardy discriminates between true ions and pseudo-ions. The latter are charged ultramicrons. 

Bromide ion acts as an inliibitor through step (9) which competes for HBr02 with the rate detennining step for the autocatalytic process described previously, step (4) and step (5). Step (8) and Step (9) constitute a pseudo-first-order removal of Br with HBr02 maintained in a low steady-state concentration. Only once [Br ] < [Br ] = /fo[Br07]//r2 does step (3) become effective, initiating the autocatalytic growth and oxidation. 

Figure B 1.16.9 shows background-free, pseudo-steady-state CIDNP spectra of the photoreaction of triethylamine with (a) anthroquinone as sensitizer and (b) and (c) xanthone as sensitizer. Details of the pseudo-steady-state CIDNP method are given elsewhere [22]. In trace (a), no signals from the p protons of products 1 (recombination) or 2 (escape) are observed, indicating that the products observed result from the radical ion pair. Traces (b) and (c) illustrate a usefiil feature of pulsed CIDNP net and multiplet effects may be separated on the basis of their radiofrequency (RF) pulse tip angle dependence [21]. Net effects are shown in trace (b) while multiplet effects can...

Read ions of Organic Halides and Pseudo-Halides... 

Some pseudo bases are stable. 1,3-Dithiolylium adds alkoxide ions at the 2-position to give stable adducts which regenerate the starting salts with acids (80AHC(27)151). Pseudo bases can also lose water to give an ether (e.g. 167 -> 168). 

Reactions catalyzed by hydrogen ion or hydroxide ion, when studied at controlled pH, are often described by pseudo-first-order rate constants that include the catalyst concentration or activity. Activation energies determined from Arrhenius plots using the pseudo-first-order rate constants may include contributions other than the activation energy intrinsic to the reaction of interest. This problem was analyzed for a special case by Higuchi et al. the following treatment is drawn from a more general analysis. ... 

Throughout this section the hydronium ion and hydroxide ion concentrations appear in rate equations. For convenience these are written [H ] and [OH ]. Usually, of course, these quantities have been estimated from a measured pH, so they are conventional activities rather than concentrations. However, our present concern is with the formal analysis of rate equations, and we can conveniently assume that activity coefficients are unity or are at least constant. The basic experimental information is k, the pseudo-first-order rate constant, as a function of pH. Within a senes of such measurements the ionic strength should be held constant. If the pH is maintained constant with a buffer, k should be measured at more than one buffer concentration (but at constant pH) to see if the buffer affects the rate. If such a dependence is observed, the rate constant should be measured at several buffer concentrations and extrapolated to zero buffer to give the correct k for that pH. 

Chlorates and bromates feature the expected pyramidal ions X03 with angles close to the tetrahedral (106-107°). With iodates the interatomic angles at iodine are rather less (97-105°) and there are three short I-O distances (177-190 pm) and three somewhat longer distances (251-300 pm) leading to distorted perovskite structures (p. 963) with pseudo-sixfold coordination of iodine and piezoelectric properties (p. 58). In Sr(I03)2.H20 the coordination number of iodine rises to 7 and this increases still further to 8 (square antiprism) in Ce(I03)4 and Zr(I03)4. 

Ingold makes no differentiation in principle between pseudo bases and those derivatives which are formed by the action of nucleophilic reagents. The latter he denotes by the general term "pseudo salts and considers their formation parallel to the formation of the car-binolamines themselves. If the mesomeric cation combines with a hydroxide ion, a pseudo base is formed if it combines with another nucleophilic ion or molecule, then a pseudo salt is formed. 

The disulfide is dissolved by aqueous potassium hydroxide, yielding a greenish-yellow solution. At low temperatures no perceptible evolution of gas takes place. Since the disulfide in many respects behaves as a pseudo-halogen, Brown et al. have supposed that the reaction described by Eq. (8) takes place, i.e. a reaction analogous to the formation of halide and halite ions from a halogen and alkali. 

In some cases the alkoxide ions have been used in large excess under pseudo-first-order conditions. ... 

Cholanic acid also possesses the ability of transporting cations across a lipophilic membrane but the selectivity is not observed because it contains no recognition sites for specific cations. In the basic region, monensin forms a lipophilic complex with Na+, which is the counter ion of the carboxylate, by taking a pseudo-cyclic structure based on the effective coordination of the polyether moiety. The lipophilic complex taken up in the liquid membrane is transferred to the active region by diffusion. In the acidic region, the sodium cation is released by the neutralization reaction. The cycle is completed by the reverse transport of the free carboxylic ionophore. 

Table 7. Pseudo-first-order rate constants, kc and K values in the Cu2 + ion catalyzed reaction of 1...

Fig. 12. Plots of pseudo-first-order rate constants for the release of p-nitrophenol from L-52 and D-52 as a function of zinc ion concentration. See Table 9 for other conditions...

The concept of oxidation number is used to simplify the electron bookkeeping in redox reactions. For a monatomic ion (e.g., Na+, S2 ), the oxidation number is, quite simply, the charge of the ion (+1, —2). In a molecule or polyatomic ion, the oxidation number of an element is a pseudo-charge obtained in a rather arbitrary way, assigning bonding electrons to the atom with the greater attraction for electrons. 

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