scholarly journals A Sulphuric Acid Reagent for the Colori-metric Determination of Testosterone

Nature ◽  
1964 ◽  
Vol 201 (4916) ◽  
pp. 296-296 ◽  
Author(s):  
LOTHAR SACHS
Keyword(s):  
Sulphuric Acid ◽  
Acid Reagent

Ferrous iron-sulphuric acid reagent for the determination of pure œstrogens

Talanta ◽  
1959 ◽  
Vol 2 (2) ◽  
pp. 183-186 ◽  
Author(s):  
Emanuel Epstein ◽  
William O. Maddock ◽  
A.J. Boyle
Keyword(s):  
Sulphuric Acid ◽  
Ferrous Iron ◽  
Acid Reagent

COMPARISON OF VARIOUS METHODS FOR THE CHEMICAL ASSAY OF CORTICOIDS IN URINE

1955 ◽  
Vol 18 (4) ◽  
pp. 374-378
Author(s):  
Mogens Sprechler
Keyword(s):  
Calibration Curve ◽  
Periodic Acid ◽  
Reducing Power ◽  
Standard Technique ◽  
Phosphomolybdic Acid ◽  
Florisil Column ◽  
Chemical Assay ◽  
Chromatographic Procedure ◽  
Acid Reagent

SUMMARY Since 1949 about 10,000 urinary corticoid analyses have been performed routinely in our laboratory. The method used for this purpose was described in 1950 (Sprechler). We determine the corticoids which can be extracted from the urine with chloroform immediately after acidification to pH 1. The extract is washed with sodium hydroxide and water, a Girard separation is performed, and finally the reducing power of the ketonic fraction is measured by means of the phosphomolybdic acid reagent reaction. During the last few years two other chemical reactions have been used for comparison: The formaldehyde and the Porter-Silber method. After a thorough examination of the above methods a standard technique was followed. In the formaldehyde method a microdiffusion in a Conway unit was used instead of distillation of the formaldehyde following the oxidation with periodic acid. The calibration curve was corrected for loss of material by taking the standard doses of DOC through all the procedures of the method. A micromodification of the Porter-Silber method was chosen. Furthermore attempts were made to determine how specific the chromatographic procedure is in the determination of steroids in urinary extracts. For this purpose the Florisil column was used, and the technique described by Nelson & Samuels was followed. Finally we have investigated the glucuronide-bound corticoids in urine in a smaller series of objects.

scholarly journals Modelling and Multi-Objective Optimization of the Sulphur Dioxide Oxidation Process

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1072
Author(s):  
Mohammad Reza Zaker ◽  
Clémence Fauteux-Lefebvre ◽  
Jules Thibault
Keyword(s):  
Sulphuric Acid ◽  
Sulphur Dioxide ◽  
Variable Number ◽  
Inlet Temperature ◽  
Multi Objective Optimization ◽  
Absorption Column ◽  
Maximum Reaction Rate ◽  
Multi Objective ◽  
Maximum Reaction

Sulphuric acid (H2SO4) is one of the most produced chemicals in the world. The critical step of the sulphuric acid production is the oxidation of sulphur dioxide (SO2) to sulphur trioxide (SO3) which takes place in a multi catalytic bed reactor. In this study, a representative kinetic rate equation was rigorously selected to develop a mathematical model to perform the multi-objective optimization (MOO) of the reactor. The objectives of the MOO were the SO2 conversion, SO3 productivity, and catalyst weight, whereas the decisions variables were the inlet temperature and the length of each catalytic bed. MOO studies were performed for various design scenarios involving a variable number of catalytic beds and different reactor configurations. The MOO process was mainly comprised of two steps: (1) the determination of Pareto domain via the determination a large number of non-dominated solutions, and (2) the ranking of the Pareto-optimal solutions based on preferences of a decision maker. Results show that a reactor comprised of four catalytic beds with an intermediate absorption column provides higher SO2 conversion, marginally superior to four catalytic beds without an intermediate SO3 absorption column. Both scenarios are close to the ideal optimum, where the reactor temperature would be adjusted to always be at the maximum reaction rate. Results clearly highlight the compromise existing between conversion, productivity and catalyst weight.

VI. The glucoside constitution of proteid matter

1894 ◽  
Vol 54 (326-330) ◽  
pp. 53-57 ◽  
Keyword(s):  
Sulphuric Acid ◽  
Cupric Oxide ◽  
The Body ◽  
Long Time

For a long time I have adopted a process for separating the glycogen of the liver consisting in boiling with potash, pouring into alcohol, and collecting the precipitate. For the purpose of estimation, the precipitated glycogen was converted by means of sulphuric acid into glucose, the determination of which gave the information required. I afterwards applied the process to blood, and the various organs and tissues of the body, with the result that a more or less notable amount of cupric oxide reducing product was obtained, which I at the time looked upon as taking origin, as in the case of the liver, from glycogen.

NEW COLOR REACTIONS OF SEDOHEPTULOSAN AND ITS DETERMINATION IN MIXTURES OF RIBOSE AND FRUCTOSE

1954 ◽  
Vol 32 (1) ◽  
pp. 14-18 ◽  
Author(s):  
L. Ujejski ◽  
E. R. Waygood
Keyword(s):  
Sulphuric Acid ◽  
Colorimetric Determination ◽  
Pure Solution ◽  
Naturally Occurring ◽  
Cysteine Hydrochloride ◽  
Color Reactions

The reagents carbazole – sulphuric acid, cysteine hydrochloride – sulphuric acid, have been applied successfully to the quantitative colorimetric determination of sedoheptulosan in pure solution or in the presence of ribose and/or fructose. Fructose can be determined quantitatively in the presence of sedoheptulosan and/or ribose by using a combination of the two reagents. Results indicate that while sedoheptulose reacts differently to sedoheptulosan with the orcinol reagent, the reactions with carbazole and cysteine are not altered by hydration and these may form a basis for the determination of the naturally occurring seven carbon sugar sedoheptulose.

Sign in / Sign up

Export Citation Format

Share Document