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.

LC–MS/MS Determination of Apigenin in Rat Plasma and Application to Pharmacokinetic Study

2020 ◽  
Vol 21 ◽  
Author(s):  
Shixing Zhu ◽  
Jiayuan Zhang ◽  
Zhihua Lv ◽  
Mingming Yu
Keyword(s):  
Formic Acid ◽  
Pharmacokinetic Study ◽  
Ammonium Acetate ◽  
Rat Plasma ◽  
Biological Properties ◽  
Plasma Samples ◽  
Supply Rate ◽  
Natural Plant ◽  
Ammonium Acetate Buffer

Background: Apigenin, a natural plant flavone, has been shown to possess a variety of biological properties. Objective: In this report, a highly selective and sensitive LC-MS/MS method was developed and validated for the determination of apigenin in rat plasma. Methods: Analysts were separated on the HSS T3 column (1.8 μm 2.1×100 mm) using acetonitrile and 0.1% formic acid in 2 mM ammonium acetate buffer at a supply rate of 0.200 mL/min as eluent in gradient model. Results: Plasma samples were treated by protein precipitation using acetonitrile for the recovery ranging from 86.5% to 90.1% for apigenin. The calibration curves followed linearity in the concentration range of 0.50-500 ng/mL. The inter-day and intra-day precisions at different QC levels within 13.1% and the accuracies ranged from -10.6% to 8.6%. Conclusion: The assay has been successfully applied to the pharmacokinetic study of apigenin in rats.

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.

scholarly journals A Novel Method for Determination of Protein in Human Serum Utilizing the Trihydroxylphenylfluorone-Molybdenum(VI) Complex as a Probe by Fluorescence Spectrometry

2007 ◽  
Vol 90 (1) ◽  
pp. 238-243 ◽  
Author(s):  
Qin Wei ◽  
Hongmin Ma ◽  
Caihong Duan ◽  
Jin Wang ◽  
Shuyuan Liu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Detection Limit ◽  
Human Serum ◽  
Fluorescence Intensity ◽  
Acetate Buffer Solution ◽  
Buffer Solution ◽  
Protein Assay ◽  
Novel Method

Abstract The fluorescence intensity of the trihydroxylphenylfluorone-molybdenum(VI) Mo(VI) complex is quenched by protein. Based on this, a novel method for protein assay in aqueous solution was developed. With pH 3.75 acetic acidsodium acetate buffer solution, in the presence of p-octyl polyethylene glycol phenyl ether microemulsion, the quenched fluorescence intensity is proportional to the concentration of bovine serum albumin (BSA) in the range of 07.00 μg/mL, and the detection limit of BSA is 5.65 ng/mL. There is no interference from amino acids and most metal ions. The method developed in this paper has been used for the successful determination of protein in human serum.

Separation of trivalent actinides from lanthanides in an acetate buffer solution using Cyanex 301

2006 ◽  
Vol 94 (5) ◽  
Author(s):  
Jack D. Law ◽  
Dean R. Peterman ◽  
Terry A. Todd ◽  
Richard D. Tillotson
Keyword(s):  
Acetic Acid ◽  
Ammonium Acetate ◽  
Separation Process ◽  
Acetate Buffer ◽  
Acetate Buffer Solution ◽  
Buffer Solution ◽  
Strip Solution ◽  
Trivalent Actinides ◽  
Separation Factors ◽  
Cyanex 301

SummaryThe separation of trivalent actinides from the lanthanides using the active extractant in the Cyanex 301 reagent, bis(2,4,4-trimethylpentyl)dithiophosphinic acid, was studied. Specifically, the extractant was studied with an ammonium acetate/acetic acid buffered feed that would result from a transuranic separation process utilizing an ammonium acetate strip solution. Separation factors of

Application of non-steroidal anti-inflammatory drugs for palladium determination

2010 ◽  
Vol 64 (6) ◽  
Author(s):  
Alaa Amin ◽  
Wafaa Hassan ◽  
Gamal Ragab
Keyword(s):  
Molar Absorptivity ◽  
Acetate Buffer Solution ◽  
Stoichiometric Ratio ◽  
Lauryl Sulfate ◽  
Buffer Solution ◽  
Palladium Determination ◽  
Highly Sensitive ◽  
Yellow Orange ◽  
Inflammatory Drugs

AbstractA highly sensitive spectrophotometric method for palladium determination using piroxicam and tenoxicam as new chromogenic reagents has been developed. In the presence of sodium lauryl sulfate (SLS), palladium reacts with piroxicam (PX) or tenoxicam (TX) to form stable yellow orange complexes in an acetate buffer solution of pH 5.0 at 424 nm and 426 nm with molar absorptivity of 7.16 × 104 L mol−1 cm−1 and 1.20 × 105 L mol−1 cm−1, respectively. Sandell sensitivity, detection, and quantitation limits were also calculated. Optimum conditions were evaluated considering pH, reagent concentration, time, temperature, and surfactant concentration. The complex system conforms to Beer’s law over the range of 0.07–1.28 μg mL−1 palladium. The stoichiometric ratio and stability constant were also evaluated. Tolerance limits of many cations and anions were determined. Finally, the proposed method was applied successfully in the determination of palladium in jewellery, anode mud, synthetic mixtures, catalysts, and alloy samples.

scholarly journals Spectrophotometric Estimation of Cefuroxime and Ceftazidime in Bulk and in Dosage Forms

2001 ◽  
Vol 69 (2) ◽  
pp. 143-150 ◽  
Author(s):  
A. Amin ◽  
H. Khalli ◽  
H. Saleh
Keyword(s):  
Molar Absorptivity ◽  
Dosage Forms ◽  
Acetate Buffer Solution ◽  
Sodium Fluorescein ◽  
Buffer Solution ◽  
Experimental Conditions ◽  
Spectrophotometric Methods ◽  
Relative Standard ◽  
Optimum Concentration Range

Three simple, accurate and sensitive spectrophotometric methods (A, B and C) for the determination of cefuroxime and ceftazidime in bulk samples and in dosage forms are described. They are based on the reaction with nitrous acid forming a nitroso derivatives which can be measured at λmax 350 and 355 nm for cefuroxime (I) and ceftazidime (II), respectively (method A) or by oxidation of drug I or II with an excess of freshly prepared hypobromite and the residual hypobromite was treated with sodium fluorescein at the optimum experimental conditions and measured at λmax at 517 nm (method B). Method C is based on the formation of tris (0-phenanthroline) iron(II) complex (ferroin) upon the oxidation of the studied drug I or II with an iron (III)-o-phenanthroline mixture in acetate buffer solution of pH 3.6 and measuring at λmax 509 nm. Regression analysis of Beer-Lambert plots showed good correlation in the concentration ranges 0.2 – 6.0, 0.2 – 3.2 and 0.1 – 5.6 μg ml−1 for methods A, B and C, respectively. The apparent molar absorptivity, Sandell sensitivity, detection and quantitation limits were calculated. For more accurate results, Ringbom optimum concentration range was 0.2 – 5.6 μg ml−1. The validity of the proposed methods was tested by analysing dosage forms containing the studied drugs I and II. The relative standard deviations were ≤ 1.25% with recoveries 98.6 – 101.4% .

scholarly journals Spectrophotometric Determination of Pipazethate Hydrochloride in Pure Form and in Pharmaceutical Formulations

2007 ◽  
Vol 90 (3) ◽  
pp. 686-692 ◽  
Author(s):  
Ragaa El-Shiekh ◽  
Alaa S Amin ◽  
Faten Zahran ◽  
Ayman A Gouda
Keyword(s):  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Pure Form ◽  
Acetate Buffer Solution ◽  
Buffer Solution ◽  
Accurate Analysis ◽  
Spectrophotometric Methods ◽  
Relative Standard ◽  
Optimum Ph

Abstract Three simple, sensitive, and reproducible spectrophotometric methods (AC) for the determination of pipazethate hydrochloride (PiCl) in pure form and in pharmaceutical formulations are described. The first and second methods, A and B, are based on the oxidation of the drug by Fe3+ in the presence of o-phenanthroline (o-phen) or bipyridyl (bipy). The formation of tris-complex upon reactions with Fe3+-o-phen and/or Fe3+-bipy mixture in an acetate buffer solution of the optimum pH values was demonstrated at 510 and 522 nm, respectively, with o-phen and bipy. The third method, C, is based on the reduction of Fe(III) by PiCl in acid medium and subsequent interaction of Fe(II) with ferricyanide to form Prussian blue, which exhibits an absorption maximum at 750 nm. The concentration ranges are from 0.5 to 8, 2 to 16, and 3 to 15 g/mL for Methods AC, respectively. For more accurate analysis, Ringbom optimum concentration ranges were calculated. The molar absorptivity, Sandell sensitivity, and detection and quantitation limits were calculated. The developed methods were successfully applied to the determination of PiCl in bulk and pharmaceutical formulations without any interference from common excipients. The relative standard deviations were 0.83% with recoveries of 98.9101.15%.

scholarly journals Determination of Mercury (II) Ion on Aryl Amide-Type Podand-Modified Glassy Carbon Electrode

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Sevgi Güney ◽  
Gülcemal Yıldız ◽  
Gönül Yapar
Keyword(s):  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Reference Electrode ◽  
Differential Pulse ◽  
Acetate Buffer Solution ◽  
Carbon Electrode ◽  
Modified Glassy Carbon Electrode ◽  
Buffer Solution

A new voltammetric sensor based on an aryl amide type podand, 1,8-bis(o-amidophenoxy)-3,6-dioxaoctane, (AAP) modified glassy carbon electrode, was described for the determination of trace level of mercury (II) ion by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). A well-defined anodic peak corresponding to the oxidation of mercury on proposed electrode was obtained at 0.2 V versus Ag/AgCl reference electrode. The effect of experimental parameters on differential voltammetric peak currents was investigated in acetate buffer solution of pH 7.0 containing 1 × 10−1 mol L−1NaCl. Mercury (II) ion was preconcentrated at the modified electrode by forming complex with AAP under proper conditions and then reduced on the surface of the electrode. Interferences of Cu2+, Pb2+, Fe3+, Cd2+, and Zn2+ions were also studied at two different concentration ratios with respect to mercury (II) ions. The modified electrode was applied to the determination of mercury (II) ions in seawater sample.

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