Particulate solid phase

Plastic is by far the most popular solid phase, since it makes the procedures extremely simple. However, plastics may also have some important limitatons (i) they are immunoreactant-consumptive, i.e. often require 10 times more reactants than particulate solid phases or membranes (ii) the avidity of immobilized antibodies for large antigens decreases by 1-2 orders of magnitude (Zwolinski, G. Jo-sephson, L. cited by Parsons, 1981), probably due to the wide spacing of epitopes or paratopes (iii) the rate of antibody-antigen interactions is slower than in solution or with particulate solid phases (hours instead of minutes), due to the necessity of the free immuno-reactant to diffuse to the solid phase (association kinetics is largely dictated by diffusion rate Section 8.4) and, (iv) few suitable antibod-... 

Particulate solid phases (agarose, cellulose, polyacrylamide, dex-tran) are very efficient since they may be dispersed throughout the reaction mixture and have a much higher ratio of surface area/ volume. Moreover, the immunoreactant is covalently bound. 

Particulate solid phases have originally been used for the separation of radiolabeled antibody-antigen complex from free labeled antibody in immunometric assays (Wide and Porath, 1966 Woodhead et al., 1974). 

Other particulate solid phases include polyacrylamide gels (Dolken and Klein, 1977), bentonite clay (Cheng and Talmage, 1969) and possibly other supports. Generally, these rarely used solid phases are not very practical and find their application only in particular cases. 

Particulate solid phases with a high surface/volume ratio (consequently higher efficiency) give faster reactions since the solid phase is dispersed throughout the reaction mixture, but may suffer from the necessity of more involved separation techniques such as centrifugation, filtration or special procedures (Hunter, 1980). This also makes automation more difficult. 

Add anti-Ig antibodies immobilized on a particulate solid phase and shake for 2 h at room temperature. 

A wide variety of hybridization conditions can be expected for this heterogeneous group of solid phases. The hybridization time depends on the nature of the solid phase and complexity of the strand in excess and may range from that comparable to membrane hybridization (Section 8.2 e.g., microtiter plates and polynucleotide probes), to a few minutes (small particulate solid phase will display a hybridization rate which approaches that of solution hybridization Table 3.16). 

This chapter will focus on fundamental concepts related to surface modification of materials utilized within polymeric biocomposites for orthopedic applications. For this chapter, orthopedic applications are defined as medical indications or procedures that benefit from utilization of polymeric biocomposites and/or additional implanted therapeutic material to aid in bone regeneration at a localized site. The term surface modification refers to the physical attachment of molecules, predominantly silanes and/or polymers, to the surface of a solid-phase material. Polymeric biocomposites are a class of biomaterials that comprises a biocompatible bulk polymer and a particulated solid phase, often referred to as a binder and a filler, respectively. As there are vast combinations of polymers and solid materials that fit this definition, this chapter highlights solely those combinations that have been utilized for orthopedic applications, in either the acadenuc or the medical industry settings. 

Solid-Phase Extractions In a solid-phase extraction the sample is passed through a cartridge containing solid particulates that serve as the adsorbent material. For liquid samples the solid adsorbent is isolated in either a disk cartridge or a column (Figure 7.17). The choice of adsorbent is determined by the properties of the species being retained and the matrix in which it is found. Representative solid adsorbents... 

Two approaches have been used to separate the analyte from its matrix in particulate gravimetry. The most common approach is filtration, in which solid particulates are separated from their gas, liquid, or solid matrix. A second approach uses a liquid-phase or solid-phase extraction. 

Extraction Eiltering limits particulate gravimetry to solid particulate analytes that are easily separated from their matrix. Particulate gravimetry can be extended to the analysis of gas-phase analytes, solutes, and poorly filterable solids if the analyte can be extracted from its matrix with a suitable solvent. After extraction, the solvent can be evaporated and the mass of the extracted analyte determined. Alternatively, the analyte can be determined indirectly by measuring the change in a sample s mass after extracting the analyte. Solid-phase extractions, such as those described in Ghapter 7, also may be used. 

Contactive (Direct) Heat Transfer Contactive heat-transfer equipment is so constructed that the particulate burden in solid phase is directly exposed to and permeated by the heating or cooling medium (Sec. 20). The carrier may either heat or cool the solids. A large amount of the industrial heat processing of sohds is effected by this mechanism. Physically, these can be classified into packed beds and various degrees of agitated beds from dilute to dense fluidized beds. 

The term three-phase fluidization requires some explanation, as it can be used to describe a variety of rather different operations. The three phases are gas, liquid and particulate solids, although other variations such as two immiscible liquids and particulate solids may exist in special applications. As in the case of a fixed-bed operation, both co-current and counter- current gas-liquid flow are permissible and, for each of these, both bubble flow, in which the liquid is the continuous phase and the gas dispersed, and trickle flow, in which the gas forms a continuous phase and the liquid is more or less dispersed, takes place. A well established device for countercurrent trickle flow, in which low-density solid spheres are fluidized by an upward current of gas and irrigated by a downward flow of liquid, is variously known as the turbulent bed, mobile bed and fluidized packing contactor, or the turbulent contact absorber when it is specifically used for gas absorption and/or dust removal. Still another variation is a three-phase spouted bed contactor. 

The test divides the drilling fluid into three phases the liquid phase, the suspended particulate phase, and the solid phase. These phases are designed to represent the anticipated conditions that organisms would be exposed to when drilling mud is discharged into the ocean. Certain drilling fluid components are water column, others are fine particulates which would stay suspended, and still water soluble and will dissolve in the other material would settle rapidly to the bottom. 

The procedure for phase separation follows the schematic in Figure 4-115 [32A]. To prepare the three test phases, a 1 9 ratio by volume of mud to seawater is mixed for 30 min. The pH is adjusted to that near seawater (pH = 7.8-9.0) by the addition of acetic acid. The slurry is allowed to settle for one hour. A portion of the supernatant is filtered through a 0.45- im filter. The filtrate is designated as the liquid phase. The remaining unfiltered supernatant of the slurry is the suspended particulate phase, while the solid phase is the settled solid material at the bottom of the mixing vessel. 

As a starting point we can view the ocean as one large reservoir to which materials are continuously added and removed (Fig. 10-17). The major sources of material include rivers and winds, which carry dissolved and particulate materials from the continents to the sea. The major removal process is the formation of marine sediments both by settling of particles through the water column as well as by precipitation of insoluble solid phases. For many ele-... 

The importance of one other type of reaction that metal ions undergo has been recognized and studied extensively in the past 40 years. This reaction is adsorption, in which metal ions bind to the surface of particulate matter and are thereby transported as part of a solid phase even though they do not form an identifiable precipitate. Conceptually, these reactions can be thought of as hybrids between complexation and precipitation reactions. Most studies of these reactions have used metal oxides or hydroxides as the solid (adsorbent) phase, and the... 

In addition to the interactions discussed above, which all depend in part on the ioniz-ability, or at least polarizability, of the surface and the adsorbates, hydrophobic parts of ligands may bind to corresponding parts of surfaces. Thus, if a metal ion is complexed or irreversibly bonded to a hydrophobic molecule, the metal may be incorporated into the bulk or surface of a particle via hydrophobic interaction between the molecule and the solid phase. Such interactions may be quantitatively significant in systems with high concentrations of dissolved and particulate organic matter. 

These reactors contain suspended solid particles. A discontinuous gas phase is sparged into the reactor. Coal liquefaction is an example where the solid is consumed by the reaction. The three phases are hydrogen, a hydrocarbon-solvent/ product mixture, and solid coal. Microbial cells immobilized on a particulate substrate are an example of a three-phase system where the slurried phase is catalytic. The liquid phase is water that contains the organic substrate. The gas phase supplies oxygen and removes carbon dioxide. The solid phase consists of microbial cells grown on the surface of a nonconsumable solid such as activated carbon. 

Beef muscle Homogenize, dilute with distilled water, centrifuge and filter to remove water-insoluble particulates extract onto solid-phase sorbents ITMS 50-100 ppb 20-50% Buchanan et al. 1995... 

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