Plastics. Phenolic resins. Determination of hexamethylene-tetramine content. Kjeldahl method, perchloric acid method and hydrochloric acid method

2006 ◽  
Keyword(s):  
Hydrochloric Acid ◽  
Perchloric Acid ◽  
Phenolic Resins ◽  
Hexamethylene Tetramine ◽  
Acid Method ◽  
Kjeldahl Method

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 Sulfur in Coal by Perchloric Acid Method

1932 ◽  
Vol 4 (2) ◽  
pp. 227-229 ◽  
Author(s):  
G. Frederick Smith ◽  
A. Garrell Deem
Keyword(s):  
Perchloric Acid ◽  
Acid Method ◽  
Sulfur In Coal

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.

Spectrophotometric Determination of Aluminum, Iron, Manganese, Phosphorus, and Titanium in Liming Materials

1964 ◽  
Vol 47 (4) ◽  
pp. 620-626
Author(s):  
P Chichilo
Keyword(s):  
Spectrophotometric Determination ◽  
Perchloric Acid ◽  
Acid Method ◽  
Aluminum Iron ◽  
Iron Manganese

Abstract Methods have been developed for the determination of aluminum with ammonium aurintricarboxylate (Aluminon); iron with 2,4,6-tripyridyl-s-triazine (TPTZ); manganese by oxidation to permanganate with KI04; phosphorus by a heteropoly blue method; and titanium with disodium-1,2-dihydroxybenzene-3,5-disulfonate (Tiron), Detertested are carried out on the filtrate obtained in the AOAC perchloric acid method for silicon. Adequacy of the directions was established by “ruggedness tests,” and the procedures were used to analyze carbonate and silicate liming materials. It is recommended that the methods be studied collaboratively.

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.

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