Buffering capacity, definition

In principle, it would be logical to combine plots of the buffer index curves of each of the buffer components of milk and thus obtain a plot which could be compared with that actually found for milk. It is not difficult, of course, to conclude that the principal buffer components are phosphate, citrate, bicarbonate, and proteins, but quantitative assignment of the buffer capacity to these components proves to be rather difficult. This problem arises primarily from the presence of calcium and magnesium in the system. These alkaline earths are present as free ions as soluble, undissociated complexes with phosphates, citrate, and casein and as colloidal phosphates associated with casein. Thus precise definition of the ionic equilibria in milk becomes rather complicated. It is difficult to obtain ratios for the various physical states of some of the components, even in simple systems. Some concentrations must be calculated from the dissociation constants, whose... 

Brpnsted theory, 23 Definition of Kb, 38 Lewis theory, 24 HSAB theory, 12 Base saturation (%), 163 Basic organic compounds, 356 Bicarbonate, 30-33 Biotite, 104, 108 Boltzmann equation, 143 Bonding, 6-12 Covalent, 7 Ionic, 7 Boron, 127 Buffer capacity, 86... 

The ability of a buffer to resist changes in pH is referred to as the "buffer capacity." Buffer capacity" can be defined.in two ways (1) the number of moles per liter of or OH required to cause a given change in pH (e.g., 1 unit), or (2) the pH change that occurs upon addition of a given amount of H" or OH (e.g., 1 mole/liter). The first definition is better because it can be applied to buffers of any concentration. 

Since (3 is related to the slope of the titration curve at one point, its value is the same whether or OH is added to the buffer. A more practical definition of buffer capacity is ... 

The path of entry of extracellular Ca " during the sustained phase of contraction in ASM has eluded definition in the absence, to date, of the demonstration of physiologically relevant VDCs or ROCs. These data raise the possibility that following agonist activation, when the buffering capacity of the sr is abolished, the passive plasmalemmal leak can provide sufficient extracellular Ca " to sustain the onist-induced, or receptor-mediated (Murray and Kotlikoflf, 1991), plateau rise in cytosolic Ca which accompanies maintained contraction. 

The definite identification and general classification of all inflow events regardless of their effects on the various deep basins can be done by the salinity conditions in the entrance sill area (Wyrtki, 1954 Wolf, 1972 Matthaus and Franck, 1992). Another occasionally used characterization of the inflow events is based on their effects on the hydrographic and chemical conditions in the central Baltic deep water (cf. e.g., Kalle, 1943 Fonselius, 1969 Nehring, 1990). The latter method has a certain drawback because the effects depend not only on the intensity of the inflows but also on the bottom topography, the density of the bottom water, and the buffering capacity of various deep basins. 

Here we restrict ourselves to pH buffers. Van Slyke (1922) defined pH buffers as substances which by their presence in solution increase the amount of acid or alkali which must be added to cause a unit change in pH. In aqueous solutions pH buffering is especially due to the interaction of weak acids and bases and their salts with water. The quantification of this effect, the buffer capacity or buffer index, is by definition... 

We can measure buffer action in terms of a definite unit called buffer capacity or buffer index x, where... 

The buffer capacity depends on the absolute concentrations of the two components buffer capacity toward addition of acid depends on the concentration of the base, while buffer capacity toward addition of base depends on the concentration of the acid. The definition of the buffer capacity can be expressed as... 

The definition of buffer capacity is p = dCJd W = -dC JdipW, where... 

Water with a Ryznar stability index less than 6.0 is definitely scaleforming indices of 6.0-7.0 are regarded as good for domestic waters possibly at values above 7.0, and certainly with indices above 7.5, the waters do not form a protective scale. One of the reasons for the discrepancies noted in the performance of waters with identical saturation indices lies in the buffer capacity of a water. 

Most historical medium formulations were supplemented with serum, tissue extracts, or other humoral fluids. As these supplements were vital to the success of the technique they undoubtedly supplied nutritional factors that were absent from the nutrient media. Although serum fractions have been characterized, total biochemical definition is a complex challenge, as it has been reported that serum contains more than 1000 proteins (Lambert and Birch, 1985). Complete characterization must identify cytokines and transport and attachment factors, as well as address other serum functions, such as pH buffering capacity, toxin inactivation, and protease activity. Such unspecified growth promotional and nutritional serum properties are perceived by users as quality. Other contributors to quality, inherent to serum supplementation, include lot-to-lot variability, availability, cost, and absence of adventitious contaminants. 

Although RDC provides a rigorous definition of the buffer capacity required to maintain the redox intensity below that associated with copper corrosion, engineering application to real... 

Treatment of buffer efficiency in general is not limited to examination of various monoprotic and polyprotic acids, but rather to the behavior of mixtures of acids. Further, from plots of buffer index vs. pH, it is easy to see that strong acids and bases are reasonable buffers for the extreme (low and high) Ph ranges. This leads to the definition of a buffer as a solution that has neutralization capacity, rather the more limited but commonly used definition as a mixture of a weak acid and its conjugate base (See Figure 8.5). 

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