Capillary isotachophoresis of piperidinoethylethers of the alkoxyphenylcarbamic acids

1986 ◽  
Vol 51 (5) ◽  
pp. 993-1000 ◽  
Author(s):  
Zdeněk Chmela ◽  
Jozef Čižmárik ◽  
Zdeněk Stránský
Keyword(s):  
Acid Medium ◽  
Steric Hindrance ◽  
Acetate Buffer ◽  
Acetate Buffer Solution ◽  
Capillary Isotachophoresis ◽  
Buffer Solution ◽  
Solution Ph ◽  
Successful Separation

Conditions for the separation and determination of N-[2-(alkoxyphenylcarbamoyloxy)-ethyl]-piperidinium chlorides ( analogues of heptacaine) by the capillary isotachophoresis have been studied. For the successful separation of lower alkoxy derivatives the acetate buffer solution, pHL = 4.75, was found to be a suitable leading electrolyte (K+ as the leading ion) and β-alanine a suitable terminator. The separation can be achieved even in the acid medium with H+ as the leading ion and with a voluminous terminating cation. For instance, pseudoaconitine or N-[2-(2-heptyloxyphenylcarbamoyloxy)-ethyl]-benzylpiperidinium chloride were found to be acceptable. The steric hindrance of the solvation, characteristic for 2-alkoxy isomers, makes their separation from 3- or 4-alkoxy isomers possible, with the exception of methoxy derivatives.

Thioglycolic acid capped CdS quantum dots as a fluorescent probe for the nanomolar determination of dopamine

2015 ◽  
Vol 7 (16) ◽  
pp. 6791-6798 ◽  
Author(s):  
Anuja Elevathoor Vikraman ◽  
Ammu Rosin Jose ◽  
Meera Jacob ◽  
Krishnapillai Girish Kumar
Keyword(s):  
Quantum Dots ◽  
Fluorescent Probe ◽  
Thioglycolic Acid ◽  
Acetate Buffer ◽  
Acetate Buffer Solution ◽  
Cds Quantum Dots ◽  
Buffer Solution ◽  
Solution Ph ◽  
Selective Determination

Thioglycolic acid (TGA) capped CdS quantum dots (QDs) have been successfully employed as an efficient nano sized fluorescent probe for the selective determination of dopamine (DA) in acetate buffer solution (pH 7).

The use of photogenerated iodine in determination of the dibazol content in solid and liquid dosage formulations

2021 ◽  
Vol 87 (2) ◽  
pp. 19-24
Author(s):  
E. V. Turusova
Keyword(s):  
Generation Time ◽  
Quantitative Estimation ◽  
Potato Starch ◽  
Analytical Signal ◽  
Acetate Buffer Solution ◽  
Molar Ratio ◽  
Buffer Solution ◽  
Solution Ph ◽  
Solid Dosage

A rapid method for the determination of Dibazol (bendazol hydrochloride) in liquid and solid dosage forms (DF) has been developed. The method is based on converting the drug into an analytical form and titrating the physiologically active compound (PAC) with a solution of photogenerated iodine obtained by irradiation of an auxiliary solution containing potassium iodide, a mixture of sensitizers (sodium eosinate: fluorescein: auramine, taken in a molar ratio of 1:1:1) and an acetate buffer solution (pH 5.6). A decrease in the titrant content in the cell due to interaction with Dibazol was recorded by a decrease in the current in the amperometric circuit. Stabilization of the current in the circuit indicated the completeness of the reaction, thus providing for estimation of the PAC content in a DF. Further irradiation of the solution and measurement of the generation time required to replenish the titrant loss in the cell also ensure the quantitative estimation of the PAC content in the preparation. The method has been tested on solid dosage form and sterile solutions of Dibazol intended for intramuscular and intravenous administration. A slight effect of stabilizers (hydrochloric acid, ethanol) and auxiliary substances (potato starch) present in the DF on the photogeneration of the titrant was observed. The determined Dibazol content in solid and liquid DF falls within the range recommended by the order of the Ministry of Health of the Russian Federation (26.10.2015 No. 751n) and OFS.1.4.2.0009.15, which indicates that the quality of the drug meets the GMP standards. The linear dependence of the analytical signal on the Dibazol concentration is observed in the range of 13.5 – 134.7 mg for the drug «Dibazol-UBF, tablets, 20 mg». The calculated limits of Dibazol detection and quantitative determination by changes in the current strength and generation time are (4.71; 3.56) and (14.26; 10.77) mg, respectively. The use of developed technique in the analysis of drugs containing Dibazol reduces both the time of single determination due to the absence of the need for standardization of solutions, and the cost of a single analysis, since it does not require the use of expensive equipment and reagents.

Effect of Sulfide Ions on the Corrosion Behaviour of Mild Steel in Acetate Buffer

1993 ◽  
Vol 58 (3) ◽  
pp. 547-554 ◽  
Author(s):  
Hyman H. Rehan ◽  
Said A. Salih ◽  
Hassan El-Daley ◽  
Ahmed G. Gad-Allah
Keyword(s):  
Mild Steel ◽  
Corrosion Behaviour ◽  
Acetate Buffer ◽  
Acetate Buffer Solution ◽  
Buffer Solution ◽  
Solution Ph ◽  
Dissolution Rates ◽  
Buffer Solutions ◽  
Sulfide Ions

The corrosion behaviour of mild steel was investigated in acidic acetate buffer solution using impendance and potential measurements. It was found that there are two dissolution rates resulting from the duplex nature of the formed oxides. The dissolution rates were found to depend on the dissolving acetate buffer solution pH and the dissolution temperature. In all cases, the film thickness was found to decrease with time of corrosion according to the relation Cm-1 = (Cm0)-1 - kdt1/2. It was found that addition of sulfide ions increases the dissolution rate and increases the rate of hydrogen evolution reaction but does not affect the mechanism of cathodic process. The role of sulfide ions on the corrosion behaviour of steel in acetate buffer solutions is revealed by the complex plane impendance analysis.

Liquid Chromatographic Determination of Taurine in Vitamin Premix Formulations

1987 ◽  
Vol 70 (5) ◽  
pp. 799-801
Author(s):  
Gowdahalli N Subba Rao
Keyword(s):  
Internal Standard ◽  
Aminocaproic Acid ◽  
Chromatographic Determination ◽  
Acetate Buffer Solution ◽  
Precolumn Derivatization ◽  
Buffer Solution ◽  
Solution Ph ◽  
Bicarbonate Buffer ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method is described for the determination of taurine in vitamin and vitamin-mineral premix formulations. The method involves extraction of taurine with 0.1 M bicarbonate buffer, followed by precolumn derivatization with dansyl chloride and LC using fluorescence detection. 6-Aminocaproic acid is used as an internal standard. A reverse phase analytical column and a mobile phase of 0.1M acetate buffer solution (pH 7.2)-acetonitrile (75 + 25) are used. Vitamins, minerals, and other excipients in the premix formulations do not interfere in the determination. The method is simple, precise, and accurate

Non-enzymatic determination of purine nucleotides using a carbon dot modified glassy carbon electrode

2019 ◽  
Vol 11 (30) ◽  
pp. 3866-3873 ◽  
Author(s):  
R. Karthikeyan ◽  
D. James Nelson ◽  
S. Abraham John
Keyword(s):  
Glassy Carbon ◽  
Low Cost ◽  
Phosphate Buffer Solution ◽  
Purine Nucleotides ◽  
Buffer Solution ◽  
Solution Ph ◽  
Carbon Dot ◽  
Enzymatic Determination ◽  
Sensitive Determination

Selective and sensitive determination of one of the purine nucleotides, inosine (INO) using a low cost carbon dot (CD) modified glassy carbon (GC) electrode in 0.2 M phosphate buffer solution (pH 7.2) was demonstrated in this paper.

Polarographic Determination of Zinc in Compounded Rubber

1950 ◽  
Vol 23 (4) ◽  
pp. 975-980
Author(s):  
F. C. J. Poulton ◽  
L. Tarrant
Keyword(s):  
Zinc Oxide ◽  
Ammonium Acetate ◽  
Potassium Thiocyanate ◽  
Acetate Buffer Solution ◽  
Acid Electrolyte ◽  
Buffer Solution ◽  
Ammonium Acetate Buffer ◽  
Ammonium Acetate Buffer Solution ◽  
Gravimetric Procedure

Abstract Reasons are advanced for the unsatisfactory nature of some of the older methods for the determination of very small amounts of zinc in compounded rubber, particularly in latex mixings. The polarographic technique offers a possible solution, but most of the commoner electrolytes for the electroreduction of this metal are alkaline, and give rise to similar errors as are met in the gravimetric procedure. The development of a suitable acid electrolyte was therefore undertaken, and ways of dealing with likely interferences were examined. The electroltye finally recommended is a potassium thiocyanate-ammonium acetate buffer solution; iron, when present, is reduced to the ferrous condition by potassium iodide. The method was used to determine zinc oxide in a series of mixings of known composition ranging from 0.8 to 40 per cent. In all except the highest proportions of zinc oxide, the figures obtained agree well with the theoretical.

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