Determination of Sulfur in Rubber by the Perchloric Acid Method

1929 ◽  
Vol 2 (1) ◽  
pp. 45-55 ◽  
Author(s):  
Edward Wolesensky
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Sulfur Content ◽  
Perchloric Acid ◽  
Steam Bath ◽  
Accurate Method ◽  
Dilute Solution ◽  
Sodium Peroxide ◽  
Rubber Compounds

Abstract In a search for a rapid and accurate method for determining sulfur in rubber it was found that oxidation of the sample by means of sodium peroxide in the Parr bomb is unsatisfactory when the sulfur content of the rubber is low because the samples that can be used for this purpose are too small for accurate results, or, if larger samples are used, the oxidation is incomplete. The use of a mixture of nitric and perchloric acids, as described by Kahane, is also unsatisfactory; but with certain modifications the method may be made to yield very good results, and if fusions are unnecessary, it will save time and labor. The chief modifications recommended are the use of a more dilute solution of nitric acid (equal volumes of the concentrated acid and water), allowing the rubber to dissolve completely on the steam bath before heating more strongly, then heating to gentle boiling until oxidation is complete, and finally destroying the residual nitric acid by means of hydrochloric acid. The use of a larger flask (500 to 800 cc.) is also recommended, and suggestions are also made for the adaptation of this method to the analysis of those rubber compounds which contain barium, lead, etc.

The Effects of Acidic Medium on the Sodium Contents Determination by FAAS

2020 ◽  
Vol 1001 ◽  
pp. 139-144
Author(s):  
Ying Li ◽  
Ben Tao Li ◽  
Guang Yu Sun ◽  
Hui Huang ◽  
Chen Gong ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Atomic Absorption Spectrometry ◽  
Flame Atomic Absorption Spectrometry ◽  
Perchloric Acid ◽  
Acidic Medium ◽  
Absorption Spectrometry ◽  
Flame Atomic Absorption ◽  
Acid Effect

The influence of different acidic medium, including hydrochloric acid, nitric acid and perchloric acid on the absorbance of sodium by flame atomic absorption spectrometry was studied. The results showed that the effects of acidic medium and water on the determination of sodium were as follows: hydrochloric acid > perchloric acid > nitric acid > water. Acid effect changed with the increase of acid concentration, however, the absorbance value of sodium element decreased when the concentration of acid was higher than 1%~2%. This effect was more obvious for high content of sodium. The detection limits, repeatability and recovery of the samples under the three acidic medium were compared. The optimum acid conditions were determined and the sensitivity of the method was improved.

Determination of Total Sulfur in Rubber and Rubberlike Materials

1943 ◽  
Vol 16 (3) ◽  
pp. 675-678 ◽  
Author(s):  
La Verne E. Cheyney
Keyword(s):  
Nitric Acid ◽  
Perchloric Acid ◽  
Potassium Nitrate ◽  
Potassium Chlorate ◽  
Sodium Peroxide ◽  
Oxide Mixture ◽  
Vulcanized Rubber ◽  
Large Numbers ◽  
Fusion Methods

Abstract The determination of total or combined sulfur in vulcanized rubber and materials of similar type involves numerous difficulties. This fact is attested by the very large number of methods which have been proposed. All the most important methods involve oxidation of the sulfur, in whatever form it may be present, to sulfate and weighing the latter as barium sulfate. The only essential differences lie in the methods of oxidation employed. The methods which seem to be the most popular at the present time are (1) oxidation of the sample in a Parr bomb with sodium peroxide, potassium chlorate, and sugar; (2) oxidation with perchloric acid and nitric acid, sometimes with the additional use of bromine; (3) oxidation with nitric acid and bromine, followed by sodium carbonate-potassium nitrate fusion; and (4) oxidation with nitric acid-zinc oxide mixture, bromine, and potassium chlorate. Serious explosions have been known to occur with perchloric acid oxidations; hence this method is not so popular at present as the other three. The fusion methods are reliable, but they are time-consuming and therefore not convenient when large numbers of samples must be handled.

DETERMINATION OF TRACE AMOUNTS OF SILVER IN GALENA ORES

1960 ◽  
Vol 38 (9) ◽  
pp. 1488-1494 ◽  
Author(s):  
E. J. Bounsall ◽  
W. A. E. McBryde
Keyword(s):  
Aqueous Solution ◽  
Nitric Acid ◽  
Sodium Chloride ◽  
Hydrochloric Acid ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Silver Content ◽  
Aqueous Sodium Chloride Solution ◽  
Aqueous Sodium

An analytical method is described for the determination of microgram amounts of silver in galena ores, based on the "reversion" of silver dithizonate. Silver is separated from relatively large amounts of lead by extraction as dithizonate into chloroform from an aqueous 1:99 nitric acid solution. Separation from mercury, which is also extracted under these conditions and would, if present, interfere in the analysis, is achieved by reverting the dithizonate solution with a 5% aqueous sodium chloride solution which is also 0.015 molar in hydrochloric acid. Following dilution of this aqueous solution and adjustment of pH, silver is again extracted into chloroform as the dithizonate, and determined absorptiometrically. Analyses of a number of galena ore samples showed a precision of within 3% for a silver content ranging from 0.03 to 0.4%.Some other methods for isolating silver from these samples, which were tried but found unsatisfactory, are discussed.

The Perchloric Method for the Determination of Sulfur in Rubber

1934 ◽  
Vol 7 (4) ◽  
pp. 730-735
Author(s):  
Ernest Kahane
Keyword(s):  
Nitric Acid ◽  
Perchloric Acid ◽  
Organic Substance ◽  
Present Author ◽  
General Idea ◽  
Organic Substances ◽  
Gutta Percha ◽  
Higher Temperature ◽  
As If

Abstract The problem of the determination of sulfur in rubber has been dealt with extensively in the literature, and it seems as if discussions and descriptions of new technic are nowhere nearly ended yet. The determination is so essential, and its rapid and precise execution is of such importance in industrial technic, that efforts in this direction should not be regarded as wasted. In 1926 and in 1927 Le Caoutchouc et La Gutta-Percha contained two articles in which the present author discussed the conditions of the determination of sulfur in rubber and then proposed the use of a new oxidizing mixture, not mentioned previous to that time, which involved the destruction of organic substances by perchloric acid. This method consisted simply in the attack on a 1-gram sample of rubber by 10 cc. of nitric acid (d. 1.39) and 5 cc. of perchloric acid (d. 1.61). Upon heating, attack by the nitric acid takes place, and this is followed by evaporation of the excess nitric acid, then at a little higher temperature there is an attack by the perchloric acid, which oxidizes the rest of the organic substance completely. This publication was concerned much more, in the determination of sulfur by the perchloric method, with the general idea of the destruction of organic substances than it was with the precise details of carrying it out. The technic had been studied somewhat superficially, as is shown by the text of the article itself.

THE APPLICATION OF 8-HYDROXYQUINOLINE TO THE ANALYSIS OF ALUMINIUM ALLOYS: DETERMINATION OF MAGNESIUM IN THE PRESENCE OF MANGANESE AND NICKEL

1945 ◽  
Vol 23b (5) ◽  
pp. 183-193
Author(s):  
Paul E. Gagnon ◽  
Henri Shehyn
Keyword(s):  
Sodium Chloride ◽  
Hydrochloric Acid ◽  
Aluminium Alloys ◽  
Accurate Method ◽  
Salting Out ◽  
Co Precipitation ◽  
Short Method

The application of the precipitation of magnesium with oxine in tartro–sodic medium to the analysis of aluminium alloys has been studied from the standpoint of possible interference from other constituents of the alloys and especially manganese and nickel. In the presence of manganese in amounts not exceeding 8.0 mgm. per 100 ml. of solution, magnesium can be successfully determined provided sodium chloride is not present. With amounts of sodium chloride exceeding 6 gm. and manganese over 6 mgm. per 100 ml. of solution, a salting-out of manganese oxinate definitely takes place which leads to high results for magnesium. This interference can be eliminated by preventing the formation of appreciable amounts of sodium chloride by evaporating off hydrochloric acid before adjusting the pH for the precipitation of magnesium oxinate. Nickel in amounts exceeding 2.5 mgm. per 100 ml. of solution interferes by co-precipitation of nickel oxinate, which is adsorbed on the magnesium oxinate and finally leads to high values for magnesium. For this reason, nickel must be removed by means of an ammonium sulphide separation for which a short method is described. With these modifications the precipitation of magnesium with oxine in tartro–sodic medium provides a rapid and accurate method of determining this element in aluminium alloys.

Determination of Lead in Bonemeal by Differential Pulse Anodic Stripping Voltammetry Using a Hydrochloric Acid Solubilization

1983 ◽  
Vol 66 (4) ◽  
pp. 985-988
Author(s):  
R Duane Satzger ◽  
Roy W Kuennen ◽  
Fred L Fricke
Keyword(s):  
Hydrochloric Acid ◽  
Rapid Method ◽  
Perchloric Acid ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Anodic Stripping ◽  
The Mean

Abstract A safe, rapid method is described for the determination of lead in bonemeal. This method uses a hydrochloric acid solubilization performed under pressure followed by determination by differential pulse anodic stripping voltammetry. This provides an alternative to a nitric-perchloric acid wet ash. Data obtained using both methods are compared. The mean recovery of a standard Pb spike was 99.2 ± 1%. The concentration of Pb in bonemeal ranged from 1.0 to 15.6 μg/g.

Determination of Free Carbon in Rubber. The Cresol Method

1941 ◽  
Vol 14 (1) ◽  
pp. 241-248 ◽  
Author(s):  
J. B. Roberts
Keyword(s):  
United States ◽  
Nitric Acid ◽  
Carbon Content ◽  
Accurate Method ◽  
The United States ◽  
Free Carbon ◽  
Simple Apparatus ◽  
Vulcanized Rubber ◽  
Acid Method

Abstract A simple, accurate method for the determination of free carbon in either raw or vulcanized rubber is presented. It has replaced the nitric acid method entirely in the laboratory of the United States Rubber Company, Detroit, Michigan. A study of the effects of interfering substances, and numerous comparisons of results by the cresol and the nitric acid methods, are given. Results by the cresol method, in the absence of interfering substances, are within 1 per cent of the calculated free carbon content. The method requires only simple apparatus readily available.

scholarly journals Behavior of transport and separation of lanthanum, yttrium and lutetium metal ions through celluose fiber supported solid membrane

2012 ◽  
Vol 31 (2) ◽  
pp. 255 ◽  
Author(s):  
Abaji G Gaikwad
Keyword(s):  
Nitric Acid ◽  
Citric Acid ◽  
Hydrochloric Acid ◽  
Metal Ions ◽  
Cellulose Fiber ◽  
Esterification Reaction ◽  
Aliquat 336 ◽  
Dilute Solution ◽  
Fiber Membrane ◽  
Source Phase

A novel idea explored was to study the behavior of transport and separation of lanthanum, yttrium and lutetium metal ions by using cellulose fiber supported solid membrane. The cellulose fiber membrane was prepared by chemical modification of cellulose fiber by esterification reaction with citric acid. Different experimental variables such as time variation, membrane length, stirrings of source and receiving phase, pH of source phase, different stripping agents  such as nitric acid, hydrochloric acid, sodium nitrate, ammonium thoicyanate, D2EHPA, TBP, Aliquat-336, tartaric acid, EDTA, organic solvents, etc in receiving phase were explored. Pre-concentration of lanthanum, yttrium and lutetium metal ions from dilute solution was carried out.

Turbidimetry of inorganic sulfate, ester sulfate, and total sulfur in urine.

1980 ◽  
Vol 26 (8) ◽  
pp. 1178-1181 ◽  
Author(s):  
P Lundquist ◽  
J Mårtensson ◽  
B Sörbo ◽  
S Ohman
Keyword(s):  
Polyethylene Glycol ◽  
Nitric Acid ◽  
Perchloric Acid ◽  
Barium Sulfate ◽  
Wet Oxidation ◽  
Total Sulfur ◽  
Sulfate Ester ◽  
Healthy Persons ◽  
Inorganic Sulfate

Abstract We describe simple and precise methods for the determination of inorganic sulfate, ester sulfate, and total sulfur in urine. The methods are based on turbidimetry of sulfate as barium sulfate in the presence of a small amount of preformed barium sulfate and with polyethylene glycol as a stabilizing agent. Inorganic sulfate is directly determined, whereas ester sulfate is measured after removal of inorganic sulfate, followed by acid hydrolysis. Total sulfur is determined after wet oxidation of the sample with nitric acid and perchloric acid in the presence of vanadate as a catalyst. We also report excretion values for healthy persons on a self-selected diet. Men excrete significantly higher amounts of inorganic sulfate and total sulfur than women, but this sex-related difference becomes insignificant if excretion values are expressed relative to creatinine.

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