IV. Note on the volumetric determination of uric acid

1888 ◽  
Vol 44 (266-272) ◽  
pp. 284-286
Keyword(s):  
Uric Acid ◽  
Nitric Acid ◽  
Silver Nitrate ◽  
Sodium Carbonate ◽  
Silver Chloride ◽  
Volumetric Determination

Dr. Haycraft has recently proposed a method for the volumetric determination of uric acid in urine ( ‘ Brit. Med. Journ.,’ 1885, 2, p. 1100) which has great advantages over all former methods in that it is much quicker and easier to manage. The uric acid from 25 c. c. of urine is precipitated by silver nitrate after previous addition of sodium carbonate (to prevent reduction) and ammonia (to dissolve silver chloride, & c.); this precipitate is then collected, washed, and dissolved in nitric acid, and the amount of silver present in this solu­tion ascertained by Volhard’s method, i . e ., titration with ammonium sulphocyanate ; from this the amount of uric acid can be calculated.

Volumetric Determination of Malathion, Using Dichlorofluorescein as Indicator

1976 ◽  
Vol 59 (1) ◽  
pp. 216-218
Author(s):  
Miguel Siquiroff ◽  
Ricardo Pollero ◽  
Rodolfo Goyena
Keyword(s):  
Standard Deviation ◽  
Petroleum Ether ◽  
Silver Nitrate ◽  
Ethyl Ether ◽  
Colorimetric Method ◽  
Florisil Column ◽  
Average Recovery ◽  
Florisil Column Chromatography ◽  
Volumetric Determination

Abstract A method has been developed which is based on alkali cleavage of malathion and volumetric determination of the resulting dimethylphosphorodithioate with silver nitrate, using dichlorofluorescein as the indicator. Pure malathion standards were analyzed by the proposed method, yielding a standard deviation of 0.27. Four typical malathion formulations containing talc, wheat flour, and anionic and nonionic emulsifiers were analyzed by both the proposed method and the former official first action colorimetric method with comparable results. Potential interferences from surfactants currently employed in liquid formulations are avoided by the use of Florisil column chromatography. Malathion is eluted from the column with petroleum ether-ethyl ether with an average recovery of 92.5%.

Volumetric determination of cobalt in Co-Sm-Fe alloys using a silver ion selective electrode in aqueous dimethylformamide and in water

1979 ◽  
Vol 44 (6) ◽  
pp. 1742-1746 ◽  
Author(s):  
Adam Košturiak ◽  
Dagmar Kalavská
Keyword(s):  
Aqueous Solution ◽  
Silver Nitrate ◽  
Silver Ion ◽  
Ion Selective Electrode ◽  
Selective Electrode ◽  
Back Titration ◽  
Volumetric Determination ◽  
Excess Sodium ◽  
Fe Alloys

A procedure is suggested for direct volumetric determination of cobalt with a sodium diethyldithiocarbaminate titrant solution in the medium of 80% dimethylformamide, using indication with a silver ion selective electrode. The procedure was applied to the cobalt determination in Co-Sm-Fe alloys. The method was adapted for the determination of cobalt in aqueous solution by back titration of excess sodium diethyldithiocarbaminate with a silver nitrate titrant solution or with generated Ag(I), using the same indication or biamperometric indication.

scholarly journals Gravimetric and volumetric determination of the purity of electrolytically refined silver and the produced silver nitrate

2007 ◽  
Vol 61 (1) ◽  
pp. 23-32
Author(s):  
Marijana Acanski ◽  
Sladjana Savatovic ◽  
Mira Radic
Keyword(s):  
Silver Nitrate ◽  
Precious Metals ◽  
Absorption Spectrometry ◽  
Electrical Contacts ◽  
Platinum Group Metals ◽  
Silver Halides ◽  
Silver Salts ◽  
Long Time ◽  
Volumetric Determination

Silver is, along with gold and the platinum-group metals, one of the so called precious metals. Because of its comparative scarcity, brilliant white color, malleability and resistance to atmospheric oxidation, silver has been used in the manufacture of coins and jewelry for a long time. Silver has the highest known electrical and thermal conductivity of all metals and is used in fabricating printed electrical circuits, and also as a coating for electronic conductors. It is also alloyed with other elements such as nickel or palladium for use in electrical contacts. The most useful silver salt is silver nitrate, a caustic chemical reagent, significant as an antiseptic and as a reagent in analytical chemistry. Pure silver nitrate is an intermediate in the industrial preparation of other silver salts, including the colloidal silver compounds used in medicine and the silver halides incorporated into photographic emulsions. Silver halides become increasingly insoluble in the series: AgCl, AgBr, AgI. All silver salts are sensitive to light and are used in photographic coatings on film and paper. The ZORKA-PHARMA company (Sabac, Serbia) specializes in the production of pharmaceutical remedies and lab chemicals. One of its products is chemical silver nitrate (argentum-nitricum) (l). Silver nitrate is generally produced by dissolving pure electrolytically refined silver in hot 48% nitric acid. Since the purity of silver nitrate, produced in 2002, was not in compliance with the p.a. level of purity, there was doubt that the electrolytically refined silver was pure. The aim of this research was the gravimetric and volumetric determination of the purity of electrolytically refined silver and silver nitrate, produced industrially and in a laboratory. The purity determination was carried out gravimetrically, by the sedimentation of silver(I) ions in the form of insoluble silver salts: AgCl, AgBr and Agi, and volumetrically, according to Mohr and Volhardt. The purity of electrolytically refined silver obtained volumetrically, according to Volhard, was 99.49%. The results suggest that the purity of electrolytically refined silver was higher than 99%. After all of these determinations, the purity of electrolytically refined silver was examined by atomic absorption spectrometry and the results confirmed that the purity of electrolytically refined silver was 99.99%. Electrolytically refined silver contained other metals: Mn, Cu, Fe, Zn, Pb, Cd, and the contents of these metals were: 1.15 ppm; 0.75 ppm; 0.65 ppm; 1.82 ppm; < 0.07 ppm and < 0.01 ppm, respectively.

The Volumetric Determination of Free Sulfur

1933 ◽  
Vol 6 (3) ◽  
pp. 412-413 ◽  
Author(s):  
A. Castiglioni
Keyword(s):  
Silver Nitrate ◽  
Nitrate Solution ◽  
Potassium Cyanide ◽  
Silver Nitrate Solution ◽  
Potassium Thiocyanate ◽  
Acetone Extract ◽  
Red Color ◽  
Volumetric Determination ◽  
Free Sulfur

Abstract In order to determine free sulfur in substances like rubber and antimony sulfide, extraction is carried out with a solvent, preferably acetone. After separation from the solvent, the extracted sulfur is converted into the sulfate and weighed as barium sulfate. With the object of making this determination, easier and simpler, it occurred to the author to determine the sulfur in the acetone extract volumetrically, instead of gravimetrically, by utilizing the observed fact that potassium thiocyanate is formed when the acetone extract is boiled with potassium cyanide. Experimental investigation of this subject showed that in the presence of an excess of potassium cyanide, conversion of the sulfur into potassium thiocyanate is quantitative, so that after evaporation of the solvent a mixture of potassium cyanide and potassium thiocyanate remains behind. To determine the potassium thiocyanate in the aqueous solution of these two salts, the method of Schulek (cf. Z. anal. Chem., 65, 433 (1924–25)) was used, which is based on the decomposition of potassium cyanide by formaldehyde. Instead, however, of adding an excess of titrated silver nitrate solution, as recommended by Schulek, and then determining the excess silver by the Volhard method, the titration was carried out directly with the silver nitrate solution, using iron nitrate as indicator, until the blood-red color of ferric thiocyanate had disappeared. In the following table are given the results of determinations by this procedure.

scholarly journals The silver voltameter. Part III.―The solvent properties of silver nitrate solutions

1914 ◽  
Vol 91 (623) ◽  
pp. 53-71 ◽  
Keyword(s):  
Silver Nitrate ◽  
Silver Chloride ◽  
Pure Water ◽  
Quantitative Measurements ◽  
Appreciable Increase ◽  
Solvent Properties ◽  
Made In ◽  
Silver Nitrate Solutions ◽  
Nitrate Solutions

In an earlier paper by Mr. F. E. Smith and a second paper by the author in conjunction with Mr. F. E. Smith it was shown that the weight of silver deposited by a given current was influenced in a very important degree by impurities in the silver nitrate solutions. The most important impurities are those which are capable of exerting a reducing action upon the silver nitrate. But there is also a group of substances to be considered which are soluble in silver nitrate solutions, though almost insoluble in water: these are precipitated when the silver nitrate solutions are impoverished at the cathode by the passage of the current and cause an appreciable increase in the weight of the deposit. They may be removed by diluting the silver nitrate solutions, filtering off the precipitation will be freely soluble in the concentrated mother-liquor from which the crystals have separated, and may be got rid of the usual way by draining on the pump and rinsing cautiously with water. In view of the importance of these impurities in the experimental determination of the electrochemical equivalent of silver, and the interest of the problem from the standpoint of the theory of solutions, it appeared to be desirable to pursue the matter further and to make quantitative measurements of the solvent properties of silver nitrate solutions for some typical substances which are insoluble, or nearly so, in pure water. The present paper includes measurements of the solubility of silver chloride, bromide, iodide, and sulphide. The solubility of the iodide has already been investigated somewhat fully by Hellwig, but only a few incidental measurements have been made in the case of the other salts.

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