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.

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.

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.

STERILIZATION OF NARCISSUS BULBS BY IMMERSION IN SILVER NITRATE — POTASSIUM CYANIDE SOLUTION IN VACUO

1933 ◽  
Vol 9 (1) ◽  
pp. 31-36 ◽  
Author(s):  
W. Newton ◽  
R. J. Hastings ◽  
J. E. Bosher
Keyword(s):  
Silver Nitrate ◽  
Tap Water ◽  
Nitrate Solution ◽  
Potassium Cyanide ◽  
Silver Nitrate Solution ◽  
Other Substances ◽  
Fly Larvae ◽  
Cyanide Solutions ◽  
Significant Injury ◽  
Selection Of

Through the use of a dye solution, evidence was obtained that a liquid disinfectant may be forced into the narcissus bulb parts invaded by nematodes and fly larvae by immersion in vacuo.An investigation of the lethal properties of solutions against nematodes and their influence upon bulb growth led to the selection of a silver nitrate solution as a promising disinfectant, but owing to instability of silver nitrate in the presence of chlorides and other substances in tap water and in dirt clinging to bulbs, its use had no commercial possibilities. However when silver salt was combined with potassium cyanide in the ratio of 1 to 3 by weight, an effective solution of satisfactory stability was obtained.A solution of silver nitrate 0.05% and potassium cyanide 0.15% by weight, forced into narcissus bulbs by an evacuation process, effectively destroyed bulb nematodes and bulb fly larvae without significant injury to bulb growth under greenhouse conditions.Field tests with bulbs treated in silver nitrate-potassium cyanide solutions resulted in the reduction of infection from 26.8 to 1%, a 96% control, and no evidence of injury in the foliage or bloom was detected.

Pulsed-laser Irradiation to Suspended Carbon Particles in Aqueous Silver Nitrate Solution

2008 ◽  
Vol 37 (8) ◽  
pp. 818-819 ◽  
Author(s):  
Yoshiko Miura ◽  
Kazuko Yui ◽  
Hiroshi Uchida ◽  
Kiyoshi Itatani ◽  
Seiichiro Koda
Keyword(s):  
Silver Nitrate ◽  
Laser Irradiation ◽  
Nitrate Solution ◽  
Pulsed Laser ◽  
Silver Nitrate Solution ◽  
Carbon Particles ◽  
Pulsed Laser Irradiation
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