Semiautomated Determination of Tridihexethyl Chloride in Meprobamate Tablets

1984 ◽  
Vol 67 (4) ◽  
pp. 677-678
Author(s):  
Ross D Kirchhoefer
Keyword(s):  
Aqueous Solution ◽  
Active Ingredient ◽  
Chloroform Solution ◽  
Semiautomated Method

Abstract A semiautomated method has been developed for the analysis of tablets containing tridihexethyl chloride in combination with meprobamate. The method is based on the USP assay for tridihexethyl chloride in tablets. The active ingredient is dissolved in water, the aqueous solution is mixed with buffer and dye solution, and the dye complex is extracted into chloroform. The absorbance of the chloroform solution is monitored at 408 nm. Results from the semiautomated method agree with I results for the USP method. Recoveries from authentic formulations I show no interference from the excipients tested.

Semiautomated Method for the Analysis of Formulations of Chlorpheniramine Maleate and Brompheniramine Maleate

1979 ◽  
Vol 62 (3) ◽  
pp. 552-555
Author(s):  
Don C Cox ◽  
Ross D Kirchhoefer
Keyword(s):  
Acid Solution ◽  
Active Ingredient ◽  
Dilute Acid ◽  
Chlorpheniramine Maleate ◽  
Precision Data ◽  
Dilute Acid Solution ◽  
Aqueous Layer ◽  
Brompheniramine Maleate ◽  
Semiautomated Method

Abstract The determination of chlorpheniramine maleate and brompheniramine maleate in tablets, capsules, injections, and elixirs has been automated. The active ingredient is dissolved in dilute HCl. The dilute acid solution is sampled, made basic with dilute NaOH, and extracted with isooctane. The isooctane phase is resampled and the drug is re-extracted into dilute HCl. The absorbance of the acidic aqueous layer is monitored at 265 nm. The method is an automated version of the general USP XIX assay for salts of organic nitrogenous bases. The results from the semiautomated procedure agree well with the USP XIX and NF XIV official methods. Recoveries were 100% from an authentic tablet material. The system is linear from 0 to 300% of declared potency. The procedure is free from common excipient and dye interferences. Precision data are included for both the automated and official methods.

Gas Chromatographic Determination of Diethylstilbestrol Dimethyl Ether in Diethylstilbestrol

1972 ◽  
Vol 55 (1) ◽  
pp. 185-186
Author(s):  
F E Gainer ◽  
W J Chiasson
Keyword(s):  
Aqueous Solution ◽  
Dimethyl Ether ◽  
Chloroform Solution ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Detector Response ◽  
Chloroform Layer ◽  
Internal Standard Peak ◽  
Linear Plot

Abstract A GLC method is described for the determination of the dimethyl ether of diethylstilbestrol (DME) in diethylstilbestrol (DES). A 1 g sample of DES is dissolved in an aqueous solution of 0.5N NaOH and then extracted with a chloroform solution containing benefin, the internal standard. An aliquot of the chloroform layer is chromatographed and the DME peak is measured relative to the internal standard peak. The method was tested for accuracy within the 11–110 ppm range and a linear plot of detector response vs. concentration was obtained.

Semiautomated Method for the Analysis of Chlorpheniramine Maleate Tablets: Collaborative Study

1979 ◽  
Vol 62 (6) ◽  
pp. 1197-1201
Author(s):  
Ross D Kirchhoefer ◽  
◽  
R L Brown ◽  
J P Gleason ◽  
S Hauser ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Excellent Agreement ◽  
Active Ingredient ◽  
Close Agreement ◽  
Collaborative Study ◽  
Chlorpheniramine Maleate ◽  
Acidic Aqueous Solution ◽  
Coefficients Of Variation ◽  
Semiautomated Method

Abstract A semiautomated method for the analysis of chlorpheniramine maleate tablets, which is based on the USP XIX general assay for salts of organic nitrogenous bases, was collaboratively studied by 6 laboratories. Collaborators were supplied with 4 composites from 4 manufacturers. In the method, the active ingredient is dissolved in dilute HC1, sampled, made basic with dilute NaOH, and extracted with isooctane. The isooctane phase is resampled and the drug is re-extracted into dilute HCL. The absorbance of the acidic aqueous solution is measured at 265 nm. The Associate Referee assayed the collaborative samples to compare the semiautomated and USP XIX methods, and found close agreement in the results from the 2 methods. In the collaborative study of the semiautomated method, there was excellent agreement of the results obtained by the collaborators. The coefficients of variation ranged from 0.46 to 2.24%. The method has been adopted as official first action.

Semiautomated Method for the Determination of Reserpine in Tablets

1970 ◽  
Vol 53 (4) ◽  
pp. 815-818
Author(s):  
Donald P Page
Keyword(s):  
Hydrochloric Acid ◽  
Colorimetric Assay ◽  
Chloroform Solution ◽  
Methanol Solution ◽  
The Other ◽  
Relative Standard ◽  
Chromatographic Procedure ◽  
Chloroform Methanol ◽  
Semiautomated Method

Abstract A chloroform solution of reserpine tablets is automatically sampled, washed successively with aqueous solutions of citric acid and sodium bicarbonate, and diluted with methanol. The chloroform-methanol solution is split into 3 streams: one flows sequentially through 2 UV spectrophotometers, recording the absorbances at 268 and 295 nm; the other 2 streams are used for the colorimetric assay (addition of hydrochloric acid and sodium nitrite) and blank (hydrochloric acid only). Day-to-day relative standard deviations were 0.40–0.95%. Comparisons with Barkan’s chromatographic procedure and the USP XVII method are presented.

Determination of Piperazine in Formulations by Nonaqueous Titration

1963 ◽  
Vol 46 (6) ◽  
pp. 1060-1062
Author(s):  
R B Maybury ◽  
R Payfer
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Perchloric Acid ◽  
Glacial Acetic Acid ◽  
Chloroform Solution ◽  
New Method ◽  
Alternative Procedure ◽  
Good Agreement

Abstract A new method is presented for the nonaqueous titration of piperazine in formulations in which the piperazine base is first brought into aqueous solution, and the solution is made strongly alkaline and extracted with chloroform. The chloroform solution of piperazine is then titrated with acetous perchloric acid to alpha-naphthol benzein indicator. The procedure is rapid, shows good agreement with other methods, and is applicable to most kinds of piperazine formulations. An alternative procedure for piperazine adipate, citrate, or tartrate in powders is given, in which the compound is dissolved and titrated directly in glacial acetic acid.

Application of Silica Nanoparticles in the Determination of Herbicides in Environmental Water Samples Using Liquid Chromatography-Mass Spectroscopy

2020 ◽  
Vol 16 (5) ◽  
pp. 748-756
Author(s):  
Mir Waqas Alam ◽  
Tentu Nageswara Rao ◽  
Yarasani Prashanthi ◽  
Vourse Sridhar ◽  
Adil Alshoaibi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Liquid Chromatography ◽  
Silica Nanoparticles ◽  
Solid Phase ◽  
Silica Nanoparticle ◽  
Environmental Water ◽  
Phase Extraction ◽  
Functionalized Nanoparticles ◽  
Supporting Material

Background: Herbicides are very beneficial in the crop yield with the aid of controlling weeds within the agriculture, but several herbicides are chronic in soil. Objective: In this study, nanoparticles and the packages of synthesized novel silica nanoparticles were studied for the preconcentration of herbicides. Methods: These nanoparticles prepared by the Stöber mechanism were purified and functionalized. Nanoparticles thus prepared successfully were used as supporting material for the preconcentration of residues of herbicides in the water. Results: Preconcentration was achieved by preparing the silica-based solid-phase-extraction cartridges. Nanoparticles used for this purpose were within the range of 50-250 nm. An SPE cartridge was prepared by packing 200 mg of silica nanoparticle in the empty cartridge of diameter 5.5 cm and length 0.6 cm in between PTFE frits. Aqueous solutions of 0.1 μg/ml of herbicides were prepared separately, and 10 ml of the solution was passed through the cartridge at the rate of 0.2 ml/min. After passing 10 ml volume of the aqueous solution, residues adsorbed on the cartridge were eluted using 2 ml of acetonitrile. The eluate was injected to determine the herbicide residue adsorbed on the SPE cartridge. Conclusion: In the study, it was found that greater than 90% of the herbicide residues were trapped on silica nanoparticle-based SPE cartridge. An analytical method was developed for the simultaneous determination of these herbicides. The residues were quantified by LC-MS/MS with ESI mode.

Enzymatic colorimetry of lecithin and sphingomyelin in aqueous solution.

1983 ◽  
Vol 29 (8) ◽  
pp. 1513-1517 ◽  
Author(s):  
M W McGowan ◽  
J D Artiss ◽  
B Zak
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Amniotic Fluid ◽  
Enzymatic Reaction ◽  
Detergent Solution ◽  
Enzymatic Determination ◽  
Red Color ◽  
Hydrolysis Of ◽  
Zwitterionic Detergent

Abstract A procedure for the enzymatic determination of lecithin and sphingomyelin in aqueous solution is described. The phospholipids are first dissolved in chloroform:methanol (2:1 by vol), the solvent is evaporated, and the residue is redissolved in an aqueous zwitterionic detergent solution. The enzymatic reaction sequences of both assays involve hydrolysis of the phospholipids to produce choline, which is then oxidized to betaine, thus generating hydrogen peroxide. The hydrogen peroxide is subsequently utilized in the enzymatic coupling of 4-aminoantipyrine and sodium 2-hydroxy-3,5-dichlorobenzenesulfonate, an intensely red color being formed. The presence of a non-reacting phospholipid enhances the hydrolysis of the reacting phospholipid. Thus we added lecithin to the sphingomyelin standards and sphingomyelin to the lecithin standards. This precise procedure may be applicable to determination of lecithin and sphingomyelin in amniotic fluid.

Determination of the effective charge on muonium during its reaction in aqueous solution

1979 ◽  
Vol 6 (1-4) ◽  
pp. 409-412 ◽  
Author(s):  
Y. C. Jean ◽  
J. H. Brewer ◽  
D. G. Fleming ◽  
D. M. Garner ◽  
D. C. Walker
Keyword(s):  
Aqueous Solution ◽  
Effective Charge
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