Differential-pulse voltammetric determination of total arsenic following its volatilization as AsH3and absorption in silver nitrate solution

1995 ◽  
Vol 32 (12) ◽  
pp. 495-497 ◽  
Author(s):  
Ada Möller ◽  
Fritz Scholz
Keyword(s):  
Silver Nitrate ◽  
Nitrate Solution ◽  
Silver Nitrate Solution ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Total Arsenic

Modified Method for the Determination of Mycotoxins in Cocoa Beans

1973 ◽  
Vol 56 (4) ◽  
pp. 1028-1030 ◽  
Author(s):  
Peter M Scott
Keyword(s):  
Silver Nitrate ◽  
Ochratoxin A ◽  
Nitrate Solution ◽  
Silver Nitrate Solution ◽  
Solvent Mixture ◽  
Cocoa Beans ◽  
Extraction Solvent ◽  
Modified Method

Abstract Method 26.026–26.030 was modified for the analysis of cocoa beans for aflatoxins by inclusion of 3% silver nitrate solution in the extraction solvent mixture. Recoveries of aflatoxins and ochratoxin A added at levels of 5–45 and 20–300 μg/kg, respectively, were satisfactory.

129. The Chlorine Content of Milk as an Indication of Mastitis

1936 ◽  
Vol 7 (1) ◽  
pp. 47-54 ◽  
Author(s):  
J. W. Blood ◽  
A. Rowlands
Keyword(s):  
Silver Nitrate ◽  
Rapid Method ◽  
Nitrate Solution ◽  
Silver Nitrate Solution ◽  
Chlorine Content ◽  
Careful Examination ◽  
Simple Test ◽  
End Point ◽  
Direct Titration

1. The importance of a rapid and simple test for the diagnosis of mastitis in cows is a question which has attracted considerable attention on the part of many workers. One such test based on the determination of chlorine in milk by a rapid method has been advocated recently by Rosell.2. The authors of this paper have made a careful examination of this method and compared the results obtained on samples of milk with those given by other methods known to yield reliable and reasonably accurate results.3. The direct titration of chlorine in milk with silver nitrate solution, without the removal of proteins, invariably gives high results, and, moreover, a satisfactory end-point is difficult to obtain.

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.

Determination of True Free Sulfur in Vulcanized Rubber. A Modification of the Thiocyanate Method

1936 ◽  
Vol 9 (1) ◽  
pp. 172-177
Author(s):  
Syukusaburô Minatoya ◽  
Itirô Aoe ◽  
Idumi Nagai
Keyword(s):  
Silver Nitrate ◽  
Nitrate Solution ◽  
Potassium Cyanide ◽  
Silver Nitrate Solution ◽  
Potassium Thiocyanate ◽  
End Point ◽  
Modified Method ◽  
Vulcanized Rubber ◽  
Free Sulfur

Abstract The limit of quantity of potassium cyanide was determined as regards the interference with the end point of the titration of potassium thiocyanate with silver nitrate solution. Acetone was found to be a suitable solvent for the separation of potassium cyanide from potassium thiocyanate. A new modified method was proposed for the determination of true free sulfur in vulcanized rubber, by the use of acetone to remove the cyanide which renders obscure the end point of the titration of thiocyanate with silver nitrate solution. The proposed method was applied to the analysis of pure sulfur and some rubber goods, and was ascertained to be accurate and easy to carry out, requiring no special apparatus.

Differential Pulse Voltammetric Determination of Piroxicam on Lanthanide Ferric Oxide Nanoparticles-Carbon Paste Modified Electrode

2018 ◽  
Vol 14 (3) ◽  
pp. 271-276 ◽  
Author(s):  
Isaac Yves Lopes de Macedo ◽  
Morgana Fernandes Alecrim ◽  
Luane Ferreira Garcia ◽  
Aparecido Ribeiro de Souza ◽  
Wallans Torres Pio dos Santos ◽  
...  
Keyword(s):  
Modified Electrode ◽  
Ferric Oxide ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Oxide Nanoparticles ◽  
Carbon Paste ◽  
Carbon Paste Modified Electrode

Polarographic and voltammetric determination of 6-mercaptopurine and 6-thioguanine

1986 ◽  
Vol 51 (11) ◽  
pp. 2466-2472 ◽  
Author(s):  
Jiří Barek ◽  
Antonín Berka ◽  
Ludmila Dempírová ◽  
Jiří Zima
Keyword(s):  
Detection Limit ◽  
Differential Pulse Voltammetry ◽  
Detection Limits ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Differential Pulse Polarography ◽  
Hanging Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Pulse Voltammetry

Conditions were found for the determination of 6-mercaptopurine (I) and 6-thioguanine (II) by TAST polarography, differential pulse polarography and fast-scan differential pulse voltammetry at a hanging mercury drop electrode. The detection limits were 10-6, 8 . 10-8, and 6 . 10-8 mol l-1, respectively. A further lowering of the detection limit to 2 . 10-8 mol l-1 was attained by preliminary accumulation of the determined substances at the surface of a hanging mercury drop.

The voltammetric determination of 4-nitrobiphenyl

1991 ◽  
Vol 56 (3) ◽  
pp. 595-601 ◽  
Author(s):  
Jiří Barek ◽  
Gulamustafa Malik ◽  
Jiří Zima
Keyword(s):  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Hanging Mercury Drop Electrode ◽  
Optimum Conditions ◽  
Mercury Drop Electrode ◽  
Working Electrode ◽  
Pulse Voltammetry ◽  
Unstirred Solution

Optimum conditions were found for the determination of 4-nitrobiphenyl by fast scan differential pulse voltammetry at a hanging mercury drop electrode in the concentration range 1 . 10-5 to 2 . 10-7 mol l-1. A further increase in sensitivity was attained by adsorptive accumulation of this substance on the surface of the working electrode, permitting determination in the concentration range (2 – 10) . 10-8 mol l-1 with one minute accumulation of the substance in unstirred solution or (2 – 10) . 10-9 mol l-1 with three-minute accumulation in stirred solution. Linear scan voltammetry can be used to determine 4-nitrobiphenyl in the concentration range (2 – 10) . 10-9 mol l-1 with five-minute accumulation in stirred solution, with the advantage of a smoother baseline and smaller interference from substances that yield only tensametric peaks.

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