scholarly journals Theoretical and Practical Considerations of the Newer Methods of the European Pharmacopeia for the Assay of Halide Salts of Organic Bases

2002 ◽  
Vol 70 (2) ◽  
pp. 129-133 ◽  
Author(s):  
Keyword(s):  
Hydrochloric Acid ◽  
Sodium Hydroxide ◽  
Potentiometric Titration ◽  
Halide Salt ◽  
Organic Bases ◽  
Halide Salts

A certain type of titration methods have appeared with an increasing frequency during the last years, this being evident surveying the latest editions of the European Pharmacopeia (1997-2001) [1-3], where there are now more than fifty monographs on the assay of halide salt of organic bases by potentiometric titration of the sample dissolved in ethanol or in an ethanolwater mixture with sodium hydroxide after addition of a defined volume of diluted hydrochloric acid [...]

scholarly journals Kinetics of Substituted Bis- and Mono-azo Dyes as Corrosion Inhibitors for Aluminium in Hydrochloric Acid and Sodium Hydroxide Solutions

1999 ◽  
Vol 23 (7) ◽  
pp. 408-409
Author(s):  
Loutfy H. Madkour ◽  
R. M. Issa ◽  
I. M. El-Ghrabawy
Keyword(s):  
Hydrochloric Acid ◽  
Sodium Hydroxide ◽  
Azo Dyes ◽  
Thermodynamic Model ◽  
Corrosion Inhibitors ◽  
Kinetics Of ◽  
Alkaline Corrosion

This investigation is designed to apply an advanced kinetic–thermodynamic model on the data obtained from acidic and alkaline corrosion of aluminium using bis- and mono-azo dyes as corrosion inhibitors.

scholarly journals Pretreatment of Wood and Char Samples

Radiocarbon ◽  
1963 ◽  
Vol 5 ◽  
pp. 342-342 ◽  
Author(s):  
Hyman Schultz ◽  
L. A. Currie ◽  
F. R. Matson ◽  
W. W. Miller
Keyword(s):  
Hydrochloric Acid ◽  
Sodium Hydroxide ◽  
Humic Acids ◽  
Large Volume ◽  
Simple Procedure ◽  
Chemical Substance ◽  
Original Material ◽  
Chemical Examination ◽  
Free Sample

It has been shown that contamination from humic acids, chitin, fungal products, etc., contributing young carbon, and from bitumen and carbonate, contributing old carbon, may not be completely removed from wood and char samples by the usual hydrochloric acid and sodium hydroxide pretreatments of the samples. A procedure is offered for the isolation of a pure chemical substance from such samples, cellulose from wood and uncombined carbon from char, that must represent the original material. Cellulose is prepared by boiling the resin-free sample in 1.25% H2SO4 and 1.25% NaOH, adding Schweitzer's reagent, filtering, and precipitating from the filtrate by acidification. Uncombined carbon is separated from char samples as the flocculant precipitate remaining after boiling in 70% HNO3, followed by settling overnight from a large volume of 6M HNO3. A simple procedure for the chemical examination of char samples is also offered for the estimation of the amounts of bitumen, carbonate, combined, and uncombined carbon in char.

scholarly journals NUCLEOPHILIC SUBSTITUTION REACTION OF CYANIDE AND METHOXYDE IONS TO QUATERNARY MANNICH BASE FROM VANILLIN

2010 ◽  
Vol 5 (3) ◽  
pp. 203-206
Author(s):  
Bambang Purwono ◽  
Estiana R. P. Daruningsih
Keyword(s):  
Nucleophilic Substitution ◽  
Mannich Reaction ◽  
Substitution Reaction ◽  
Mannich Base ◽  
Nucleophilic Substitution Reaction ◽  
Substitution Reactions ◽  
Halide Salt ◽  
Leaving Group ◽  
Dimethyl Amine ◽  
Halide Salts

The nucleophilic substitution reaction to quaternary Mannich base from vanillin has been investigated. Mannich reaction to vanillin was carried out by refluxing mixture of vanillin, formaldehyde and dimethyl amine. Quaternary ammonium halide salt was obtained from reaction of Mannich vanillin base with methyl iodide in THF solvents and yielded 93.28 %. Nucleophilic substituion to the halide salts with cyanide nucleophile produced 4-hidroxy-3-methoxy-5-(cyano)methylbenzaldehyde in 54.39% yield. Reaction with methoxyde ion yielded 4-hydroxy- 3-methoxy-5-(methoxy) -methylbenzaldehyde in 67.80% yield. The nucleophilic substitution reaction showed that trimethylamino substituent of quaternary Mannich base can act as a good leaving group on nucleophilic substitution reactions. Keywords: Mannich reaction, vanillin, nucleophilic substitution

Potentiometric Titration of Salts of Organic Bases in Acetic Acid

1952 ◽  
Vol 24 (2) ◽  
pp. 300-306 ◽  
Author(s):  
C. W. Pifer ◽  
E. G. Wollish
Keyword(s):  
Acetic Acid ◽  
Potentiometric Titration ◽  
Organic Bases

Hydrohalogenation of Unactivated Alkenes Using a Methanesulfonic Acid/Halide Salt Combination

Synthesis ◽  
2021 ◽  
Author(s):  
Jean-François Paquin ◽  
Xavier Bertrand ◽  
Pascal Paquin ◽  
Laurent Chabaud
Keyword(s):  
Acetic Acid ◽  
Methanesulfonic Acid ◽  
Alkyl Halides ◽  
Halide Salt ◽  
Acid Halide ◽  
Halide Salts

AbstractThe hydrochlorination, hydrobromination, and hydroiodination of unactivated alkenes using methanesulfonic acid and inorganic halide salts (CaCl2, LiBr, LiI) in acetic acid are reported. This approach uses readily available and inexpensive reagents to provide the alkyl halides in up to 99% yield. An example of deuteriochlorination using deuterated acetic acid as the solvent is also demonstrated.

scholarly journals Determination of Uric Acid

1967 ◽  
Vol 13 (1) ◽  
pp. 12-18 ◽  
Author(s):  
H Harold Nishi
Keyword(s):  
Uric Acid ◽  
Hydrochloric Acid ◽  
Sodium Hydroxide ◽  
Serum Sample ◽  
Colorimetric Procedure ◽  
Sodium Hydroxide Treatment

Abstract The Archibald colorimetric procedure for determination of uric acid has been adapted for automation. The major differences from the original manual procedure after sodium hydroxide treatment of the serum sample are neutralization with hydrochloric acid and dialysis of the serum instead of precipitation to remove protein. At the rate of 40 samples per hour, the automated procedure shows good correlation with the manual procedure.

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