Metal solutions, carrier added

The linking of a metal to an antibody could, in principle, be accomplished by forming the metal chelate either prior to or after attachment to protein. Success to date has been achieved only by formation of the protein-ligand conjugate before metal chelation. The complexation reaction has several general features. First, reactions between the metallic radionuclides and antibodies are almost always performed with sub-stoichiometric quantities of chelate and metal ion. It is therefore of the utmost importance that no carrier added metals obtained from commercial sources be exceedingly pure or else be purified prior to use. Reactions of "carrier added" metal solutions are not likely to be of use because of the ease with which available chelate sites become saturated. Because the formation of chelate complexes is usually a bimolecular reaction, the complexation will proceed optimally when more chelation sites are available. Similarly, the more isotope in solution, the faster the reaction. Employment of a carrier chelate to insure solubilization of the radiometal is of value to maximize available isotope and the acetate ion has proven useful. 

Orthophosphate Hquid mixtures are ineffective as micronuttient carriers because of the formation of metal ammonium phosphates such as ZnNH PO. However, micronutrients are much more soluble in ammonium phosphate solutions in which a substantial proportion of the phosphoms is polyphosphate. The greater solubiHty results from the sequestering action of the polyphosphate. The amounts of Zn, Mn, Cu, and Fe soluble in base solution with 70% of its P as polyphosphate are 10 to 60 times their solubiHties in ammonium orthophosphate solution. When a mixture of several micronutrients is added to the same solution, the solubiHty of the individual metals is lowered significantly. In such mixtures the total micronuttient content should not exceed 3% and the storage time before precipitates appear may be much shorter than when only one micronuttient is present. 

Diastereomer ratios were determined by gas chromatography. Since the aldol adduct undergoes retroaldol reaction on the column, it must be silylated prior to injection. Approximately 5 mg of the crude adduct is filtered through a short plug of silica gel to remove any trace metals. The material is taken up into 1-2 mL of dichloromethane in a 2-raL flask or small test tube. To this solution are added 4-5 drops of N,N-diethyl-1,1,1-trimethylsilylamine and a small crystal of 4-(N,N-dimethylamino)pyridine (Note 11), The solution is stirred for 2 hr and injected directly onto the column. (Column conditions 30 m x 0.32 mm fused silica column coated with OB 5, 14 psi hydrogen carrier gas, oven temperature 235°C). 

For the chemical separation, the irradiated bismuth is dissolved in acid, tellurium carrier is added, and metallic polonium and bismuth are precipitated from solution with stannous chloride (96, 117). The metals are dissolved in acid and the tellurium reprecipitated with sulfur dioxide (76), leaving polonium in solution in the bipositive state. 

The electrochemical procedure for the synthesis of the complex was similar to those described by Tuck [559]. The cell was a 100-cm3 tail-form beaker fitted with a rubber bung through which the electrochemical leads enter the cell. The indium anode was suspended from a platinum wire and the cathode was a platinum wire. [(pySe)2] (0.31 g) was dissolved in acetonitrile and a small amount of tetraethylammonium perchlorate was added to the solution as a current carrier. An applied voltage of 10 V produced a current of 15 mA. During the electrolysis nitrogen gas was bubbled through the solution to provide an inert atmosphere and also to stir the solution phase. After 1 hr of reaction 70 mg of metal had been dissolved from the anode (Ey = 1.1). 

The absorption of ozone by cyanide solutions in stirred reactors is complicated by mass transfer considerations. The presence of ozone gas in the exhaust from such a reactor does not indicate that equilibrium has been obtained between ozone gas bubbles and ozone in solution, but rather that the mass transfer through the individual bubbles is not complete, because of the resistance on the gas side. In other words, mass transfer controls the reaction, as the ozone will react almost instantaneously with the cyanide ion in solution. The presence of some metals, particularly copper, appears to speed up the absorption by acting as oxygen carriers. A solution of ozone in dilute acid decomposes somewhat more quickly when a trace of cupric ion is added. The presence of these metal catalysts, if this be their function, does not appear to be a necessary condition to ozone oxidation. What is important is that adequate mass transfer time and surface be available, as would be found in a countercurrent packed tower. 

A solution of a pertinent amount of ruthenium chloride (RuCb.x H2O (x < 1), Aldrich) and tin precursor (SnCb, Aldrich) was stirred for 30 minutes at 333 K in 1,2-ethanediol (p.a). Added molar amount of 1,2-ethanediol was 2/1 compared to carrier precursor (Si(OC2Hs)4) molar amount. Tetraethoxysilane (98%, Aldrich) was inserted to the cooled solution of metal precursors under stirring at a room temperature. Acquired mixture was heated to 343 K and stirred at this temperature for 3 hours. Then, a stoichiometric excess of distilled water (90 ml) was added to the solution and the solution was further stirred at 343 K until a gel formed. 

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