Diluent solution

In the iodimetric titration procedure, the combustion gases are bubbled through a diluent solution containing pyridine, methanol, and water. This solution is titrated with a titrant containing iodine in a pyridine, methanol, and water solution. In automated systems, the titrant is delivered automatically from a calibrated burette syringe and the endpoint detected amperometrically. The method is empirical, and standard reference materials with sulfur percentages in the range of the samples to be analyzed should be used to calibrate the instrument before use. Alternative formulations for the diluent and titrant may be used in this method to the extent that they can be demonstrated to yield equivalent results. 

Figure 7.23 summarizes the four possible different organizations found in some extractant/diluent solutions. The presence in a given system of any of the four microstructures described here could have profound consequences on its dynamic and kinetic properties. 

Most of the studies focused on the influence of CMPO radiolysis on two important steps of the TRUEX process for americium recovery extraction and stripping. The effect of radiolysis on CMPO-diluent solutions was extremely different under these two process conditions (see Table 8.5), with a major increase in Z)Am values at pH 2, but a moderate decrease for 2-3 mol L 1 HN03. 

Diluent, Solution A, Solution B, Mobile phase, and Chromatographic system Proceed as directed in the Assay. 

Chemistry. Dibutyl butyl phosphonate [DBBP = (C4H9O72TC4H9TPO]- diluent solutions extract Am(III) and HNO3 from aqueous nitrate media according to the reactions shown in Equations (1) and (2), respectively ... 

Siddall(8j and others have observed that DBBP-diluent solutions extract Pu(IV) exceedingly well from both strong HNO3 solutions and from metal nitrate-low HNO3 solutions. The greater affinity of DBBP for Pu(IV) over that for Am(III) makes it possible to use dilute (0.1-0.25M) HNO3 solutions to selectively partition americium from co-extracted plutonium. The resulting... 

According to Stoeppler et al. [15], severe errors up to a factor of two may result from ETA—AAS analysis of biological materials without some form of sample pretreatment. The approaches that will be discussed here are (a) the use of diluent solutions to minimise matrix and molecular absorption interferences (b) partial decomposition techniques in which metals are extracted from proteins with acids (c) dissolution of tissue samples without complete oxidation (d) complete oxidation procedures such as dry ashing, wet digestion at ambient and elevated pressures, and low temperature ashing with reactive gases at low pressures. 

Choosing the buffer Wavelength considerations Choosing the Diluent Solution stablllty/solublllty Considerations... 

Suspension products (Table 4) are prepared by combining sterile vehicle and sterile drug powder asepti-cally or by combining two sterile solutions, with the drug solution precipitating in the diluent solution. 

Batch contact studies have shown that both Am(III) and Pu(IV) transfer rapidly at 23 to 25°C between DHDECMP-diluent solutions and aqueous HNO3. In all tests conducted, equilibrium was reached in <30 seconds. 

In practice, clinical laboratories are able to purchase materials from one of several companies that manufacture control sera or control products. These are generally sup-phed as liquid or lyophilized materials that are reconstituted by adding water or a specific diluent solution. Also available are materials having matrices representing urine, spinal fluid, and whole blood. Liquid control materials are also available and have the potential advantage of eliminating errors caused by reconstitution. However, the matrices of these liquid materials contain other materials that may be a potential source of error with some analytical methods and instruments. 

Hypoxia resulting from the home use of nebulizers has been reported. This would appear to result from misuse of the devices. Indeed, patient misuse may not be the only problem. A poll of 67 physicians with a stated interest in chest disease showed that there was a significant difference in their prescribing of (3-adrenergic receptor agonists for delivery by nebulizer [129]. There was a fivefold difference in the dose of albuterol, a 20-fold difference in the volume of the diluent solution, and a 10-fold variation in the flow of gas driving the nebulizer that the physicians used. Undoubtedly, some of this variation may be attributed to the use of different devices. However, implicit in these observations is a significant potential dose-delivery problem. 

As in gas absorption and distillation, liquid extraction requires that two phases be brought into intimate contact with each other to ensure transfer of the solute from the diluent to the solvent, and then separated. In absorption and distillation there are two phases (liquid and vapor) with signiticantly different densities. This is not the case with extraction where both solvent and diluent solutions are liquids, often with similar densities. Because of this and the immiscibility requirement, the two liquids are often difficult to mix and even more difficult to separate. In addition, liquids have sufficiently high viscosities that they require pumps to maintain flow. Most extraction processes include mechanical energy for pumping, mixing, and separating the liquids. 

W. Davis, Jr. October 1962. Thermodynamics of extraction of nitric acid by tri- -butyl phosphate hydrocarbon diluent solutions I. distribution studies with TBP in Amsco 125-82 at intermediate and low acidities. Nuc. Sc. Eng. 14 (2) 159-168. 

However, in coupled transport a more complex behavior is observed. Figure 9.18 shows a plot of the uranium flux vs the same amine in a membrane. The flux reaches a maximum value at about 30% amine in the diluent and decreases with increasing concentration thereafter. This appears to be a general phenomenon as, for example. Figure 9.19 illustrates with the flux of copper through various reagent-diluent solutions. The pattern of the results is similar to Figure 9.18. 

The pHhn method measures basicity as apparent from HCl extraction. Extraction through ion-pair formation (as is the case for HCl extraction by any aliphatic amine) or through binding with partial ion-pair nature is strongly dependent on stabilization by polar and protic diluents. The pHhn, thus, depends on the diluent. Solutions of 0.5 mol/kg tricaprylyl amine [T(OD)A, Henkel s Alamine 336 in kerosene, xylene, nitrobenzene, tribu-tylphosphate, and -octanol showed pHhn values of 3.50, 3-52, 3.62, 3.88, and 4.16, respectively [44. ... 

As far back as in the late 1940s to the early 1950s, it was noticed that if the suspension copolymerization of mono- and divinyl monomers is carried out in the presence of an inert solvent, it wiU yield beads that are opaque in appearance and much more resistant to osmotic shock compared with the known gel-type copolymers. It soon became evident that the improved physical properties of the new resins are caused by their special internal structure, which, in its turn, results from the phase separation of the initially homogeneous comonomer—diluent solution. This finding opened the door to a new generation of polymeric adsorbents, the so-called macroporous resins that exhibit stable porosity in both the dry and the solvated states. 

Drugs exhibit a number of possible hazards in addition to toxicity. Anaesthetic ether (diethyl ether, 60-29-7) forms extremely explosive and poisonous substances on exposure to atmospheric oxygen sodium hypochlorite and hydrogen peroxide used as antiseptics are oxidizers multiple acids, metals, metal salts, and bases are used. In addition, drugs are rarely administered pure. Instead, they are coupled with solvents, diluents, solutions, and administered by aerosol sprays, etc., which may represent hazards. 

All considered, it is not obvious how to obtain an appropriate ACp to use in a landscape height calculation or indeed if the concept of a landscape limit is a useful one for polymers (although the coincidence of Tc and a- bifurcation temperatures seen in Fig. 2 would suggest that it should be). It is possible that one could use Tc/Tg ( = Tx/Tg) value to back-calculate an effective contributing ACp value. This is an area for further work, in which an investigation of the effect of diluent concentration on ACp for the binary polymer diluent solutions, could play a useful role. 

Diluent solution l.OM sucrose (Sigma-Aldrich S1888) in PBS containing 3mg/mL BSA (Sigma-Aldrich A4161), sterile filtered. 

With online haemo(dia)filtration the dialysis machine produces the diluent solution near the patient, so-called online . In some countries the pharmacist is responsible for the quality of the solutions, because health inspectorate regards this as the preparation of a medicine. 

Thermally-induced phase separation (TIPS) has been shown to be an excellent way to make microporous polymeric membranes. Microporous membranes are generally prepared by TIPS process, which is based on the phenomenon that the solvent quality decreases when the temperature is decreased. On removing the thermal energy by cooling or quenching, a polymer-diluent solution phase separation occurs. After the phase separation, the diluent is removed, typically by solvent extraction, and the extractant is evaporated to yield a microporous structure. Typically, the TIPS process has been used to produce isotropic structures that is, the pore size does not vary with direction in the membrane. A few studies have been reported on the formation of... 

Add 15.00 ml of sample to a 200-ml spoutless tail-form beaker by means of the automatic Knudsen-type pipette and add 15 ml of indicator-diluent solution. The titration is made from a Knudsen-type automatic bulb burette, the graduations of which generally commence at about 16.7. (This burette delivers twice the volume indicated by the graduations, to obtain an increased sensitivity.) The contents of the beaker must be vigorously stirred before and at the endpoint. It is best to commence stirring after the bulb has about two thirds emptied. About 1 ml before it is judged that the end point is reached rinse the sides of the beaker with a little distilled water from a wash bottle. 

Figure 3. Plot of net weight gain (%) in 1/4" PMMA rod versus time elapsed after removal from the final treatment solution. Data is indicated for an infusion experi-ment in which PMMA is treated with a diluent solution containing 50%/50% water/poly(ethylene glycol) (above) and 100% water (below).

In order to demonstrate how uniformly the infusion process modified the polymer samples, we examined the relationship of the rate of dilution on the penetration depth of the infusant in the infused sector. The results for a series of infusion experiments with PVP alone are shown in Table 1. The concentration of the starting solution and diluent solution for all of these samples, as indicated in the experimental section, were identical. The only parameter varied was the rate at which the diluent solution was added to the system. Overall, these studies revealed that the penetration depth is inversely proportional to the dilution rate. Thus, the infusion depth can be controlled by regulating the rate of dilution. Moreover, the infused region is uniformly treated as seen in the constant value for the percentage weight gain in the infused region. 

Figure 4. Three PMMA disks after treatment by the chemical infusion process with 35% PVP and (a) 0, (b) 5, and (c) 50% titanium (IV) isopropoxide in the diluent solution.

Figure 5. Cross section of a PMMA disk treated with a diluent solution containing 40% titanium (IV) isopropoxide and 21% PVP at lOOx magnification. The top of the sample is the boundary between the top (dark) and middle layers. The middle layer corresponds to the infused sector of 280 m while the bottom layer is the untreated polymer. Note the sharp interface between the infused region and the untreated PMMA region.

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