Uranyl acetate reagent

Umbelliferone, pH-dependent change of fluorescence color 44 Universal reagents 4,46,195,376,402,405, 412, 430, 434 Uracil derivatives 44,45 Uranium cations 144 Uranyl acetate reagent 44 Urea... 

K) Sodium salts, are detd gravimetrically by means of magnesium uranyl acetate reagent, using a 20g sample. As this, rather tedious method, is essentially the same as described in the literature(See Ref 3,pp 879-81 and Ref 8,pp 558-60), no description is given here... 

The catalyst was prepared by 72-hour treatment of 100 gm of Linde sodium sieve with 1700 ml of 22.1 wt % ammonium nitrate. During this period the slurry was occasionally stirred. The slurry was filtered, and after working the solid several times with water, it was dried at room temperature. The amount of sodium ion replaced by ammonium ion was determined by analyzing the filtrate for sodium using the magnesium uranyl acetate reagent. The extent of replacement was found to be 52% and this compared favorably with the results of Turkevich and Ciborowski (3), who found, using the same method of preparation but a different method of analysis, a 56% replacement. 

Zinc uranyl acetate (reagent for sodium). Dissolve 10 g of U02(C2Hj,02)2-2H20 in 6 g of 30% acetic acid with heat, if necessary, and dUute to 50 mL. Dissolve 30 g of ZnlCjHjOj) - in 3 g of 30% acetic acid and dUute to 50 mL. Mix the two solutions, add 50 mg of NaCl, allow to stand overnight and filter. 

The larger cations of Group 1 (K, Rb, Cs) can be precipitated from aqueous solution as white solids by addition of the reagent sodium tetraphenylborate, NaB(C( H5)4. Sodium can be precipitated as the yellow sodium zinc uranium oxide ethanoate (sodium zinc uranyl acetate). NaZn(U02)3(CH3C00)y. 9H2O. by adding a clear solution of zinc uranyl acetate in dilute ethanoic acid to a solution of a sodium salt. 

The reagent is prepared as follows. Dissolve 10 g uranyl acetate in 6g glacial acetic acid and 100 ml water (solution a). Dissolve 33 g magnesium acetate in 10 g acetic acid and 100 ml water (solution b). Mix the two solutions a and b, allow to Stand for 24 hours, and filter. Alternatively, a reagent of equivalent concentration may be prepared by dissolving uranyl magnesium acetate in the appropriate volume of water or of m acetic acid. 

Uranyl zinc acetate reagent. Dissolve 10 g uranyl acetate dihydrate, U02(CH3C00)2,2H20, in a mixture of 5 ml glacial acetic acid and 20 ml... 

The classic reagent for qualitative and quantitative determination of sodium is uranyl acetate, which in the presence of sodium and a divalent metal cation gives a precipitate of NaM(U02)3(CH3C00)9, where M could be Mg, Zrf+, Co +, Ni + or others. However, since uranium is very poisonous and radioactive, tests based on these reagents have been replaced with tests based on sodium s reactivity toward pyroantimonate and methoxyphenylacetic. 

Buffers and Reagents. Nucleation of clathrin lattices by API80 or AP2 was studied HKM buffer, consisting of 25 mM Hepes pH 7.4, 125 mM potassium acetate, 5 mM magnesium acetate, and 1 mM dithiothreitol. Lipid stocks and uranyl acetate stocks were prepared as above. 

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