scholarly journals DEVELOPMENT AND VALIDATION OF ANALYTICAL METHOD FOR QUANTIFICATION OF ACETIC ACID CONTENT IN AMLODIPINE BESYLATE

2019 ◽  
pp. 8-11
Author(s):  
Sk Manirul Haque ◽  
Ayman Ahmad
Keyword(s):  
Acetic Acid ◽  
Sodium Hydroxide ◽  
Acid Content ◽  
Amlodipine Besylate ◽  
Strong Base ◽  
Titrimetric Method ◽  
Acetic Acid Content ◽  
Ich Guidelines ◽  
Relative Standard ◽  
Limit Of Quantitation

Objective: To develop and validate a simple and accurate cost-effective titrimetric method according to International Conference Harmonization (ICH) guidelines for acetic acid content in Amlodipine Besylate. Methods: The titration based on general acid-base reaction to form water and salt. Sodium hydroxide act as a strong base and titrated against weak acid (acetic acid). Phenolphthalein used as an indicator and colorless to pink is the endpoint. Sodium hydroxide is standardized with primary standard potassium hydrogen phthalate. Results: The method was linear in the range of 0.75 to 30.25 μg/ml with a correlation coefficient 0.9999. Limit of detection (LOD) and limit of quantitation (LOQ) value were found to be 0.61 and 1.85 μg/ml, respectively. The percentage recovery (98.20–99.97%) and percentage relative standard deviation (%RSD) is less than 2% within the acceptable limit of ICH guidelines. The robustness and ruggedness results were excellent. Method is accurate and precise, no interference from excipients. Conclusion: A new analytical titrimetric method was developed and validated as per ICH guidelines for the determination of acetic acid content in amlodipine. This proposed method applied for routine analysis of acetic acid content in bulk and pharmaceutical formulations of amlodipine besylate.

Determination of subnanogram amounts of sulfur dioxide and sulfites by pneumatopotentiometry

1986 ◽  
Vol 51 (10) ◽  
pp. 2077-2082 ◽  
Author(s):  
Jan Langmaier ◽  
František Opekar
Keyword(s):  
Sulfur Dioxide ◽  
Redox Potential ◽  
Sodium Hydroxide ◽  
Porous Membrane ◽  
Membrane Electrode ◽  
Iodine Monochloride ◽  
Membrane Pores ◽  
Relative Standard ◽  
Limit Of Quantitation

Gold porous membrane electrode has been used for the potentiometric determination of small amounts of sulfur dioxide absorbed in the solutions of sodium tetrachloromercurate or sodium hydroxide. Sulfur dioxide is released by the reaction with an acid into a stream of nitrogen and led to the electrode immersed into the solution of iodine monochloride. Part of SO2 penetrates through the membrane pores into the solution where it is oxidized. The electrode redox potential change is a measure of the SO2 concentration in the absorption solution. In the solution of 1 . 10-5 M[ICl2]- in 0.02 M-HClO4 the limit of quantitation was found to be 0.07 ng SO2 . ml-1. The relative standard deviations of 1.4% and 2.5% were found for the determinations of 10 ng and 0.5 ng of SO2, respectively. Higher concentrations of H2S interfere only in the hydroxide solution. About 10 samples can be analyzed per one hour.

scholarly journals Effect of Co-Inoculation with Saccharomyces cerevisiae and Lactic Acid Bacteria on the Content of Propan-2-ol, Acetaldehyde and Weak Acids in Fermented Distillery Mashes

2019 ◽  
Vol 20 (7) ◽  
pp. 1659
Author(s):  
Katarzyna Pielech-Przybylska ◽  
Maria Balcerek ◽  
Grzegorz Ciepielowski ◽  
Barbara Pacholczyk-Sienicka ◽  
Łukasz Albrecht ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Acid Content ◽  
Isopropyl Alcohol ◽  
Quantitative Composition ◽  
Acetic Acid Content ◽  
Initial Ph

The qualitative and quantitative composition of volatile compounds in fermented distillery mash determines the quality of the obtained distillate of agricultural origin (i.e., raw spirit) and the effectiveness of further purification steps. Propan-2-ol (syn. isopropyl alcohol), due to its low boiling point, is difficult to remove by rectification. Therefore, its synthesis needs to be limited during fermentation by Saccharomyces cerevisiae yeast, while at the same time controlling the levels of acetaldehyde and acetic acid, which are likewise known to determine the quality of raw spirit. Lactic acid bacteria (LAB) are a common but undesirable contaminant in distillery mashes. They are responsible for the production of undesirable compounds, which can affect synthesis of propan-2-ol. Some bacteria strains are able to synthesize isopropyl alcohol. This study therefore set out to investigate whether LAB with S. cerevisiae yeast are responsible for conversion of acetone to propan-2-ol, as well as the effects of the amount of LAB inoculum and fermentation parameters (pH and temperature) on the content of isopropyl alcohol, acetaldehyde, lactic acid and acetic acid in fermented mashes. The results of NMR and comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry (GC × GC-TOF MS) analysis confirmed the ability of the yeast and LAB strains to metabolize acetone via its reduction to isopropyl alcohol. Efficient fermentation of distillery mashes was observed in all tested mashes with an initial LAB count of 3.34–6.34 log cfu/mL, which had no significant effect on the ethanol content. However, changes were observed in the contents of by-products. Lowering the initial pH of the mashes to 4.5, without and with LAB (3.34–4.34 log cfu/mL), resulted in a decrease in propan-2-ol and a concomitant increase in acetaldehyde content, while a higher pH (5.0 and 5.5) increased the content of propan-2-ol and decreased acetaldehyde content. Higher temperature (35 °C) promoted propan-2-ol synthesis and also resulted in increased acetic acid content in the fermented mashes compared to the controls. Moreover, the acetic acid content rose with increases in the initial pH and the initial LAB count.

Preparation and Properties of Acidified Prevulcanized Natural Rubber Latex

2014 ◽  
Vol 997 ◽  
pp. 239-242
Author(s):  
Guang Lu ◽  
He Ping Yu ◽  
Yong Zhou Wang ◽  
Yong Yue Luo ◽  
Zong Qiang Zeng
Keyword(s):  
Tensile Strength ◽  
Acetic Acid ◽  
Natural Rubber ◽  
Acid Content ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Acetic Acid Content ◽  
Hot Air ◽  
Aging Resistance

After a maturation of three days at ambient temperature, the sulfur-prevulcanized natural rubber latex (SNRL) was stabilized by 20wt% Peregal O, and then acidified with the 36wt% acetic acid by a ratio of 5, 15, 25, 35 and 45 g of 36wt% acetic acid to 100g SNRL, to obtain acidified prevulcanized NR latex (ASNRL) with different acidity, respectively. The viscosity of ASNRL increased, while the nitrogen content decreased, with the increment of acetic acid content and the decrease in pH; for unaged samples, the tensile strength, elongation at break, 300% and 500% moduli of the ASNRL films were only slightly lower than those of SNRL film; however the hot-air aging resistance decreased with the increment of acetic acid content.

scholarly journals Titrimetric and sensitive spectrophotometric methods for the assay of quetiapine fumarate in pharmaceutical formulations

2011 ◽  
Vol 17 (1) ◽  
pp. 99-106
Author(s):  
Basavaiah Vinay ◽  
Oddarevanna Revanasiddappa ◽  
Jagannathamurthy Ramesh ◽  
Nagaraju Rajendraprasad
Keyword(s):  
Acetic Acid ◽  
Perchloric Acid ◽  
Pharmaceutical Formulations ◽  
Developed Countries ◽  
Calibration Graph ◽  
Quetiapine Fumarate ◽  
Titrimetric Method ◽  
Accuracy And Precision ◽  
Relative Standard

Quetiapine fumarate (QTF) is a selective monoaminergic antagonist with high affinity for the serotonin Type 2 (5HT2), and dopamine type 2 (D2) receptors. Titrimetric and spectrophotometric assay of quetiapine fumarate (QTF) using perchloric acid and acetic acid as reagents are described. The first method (method A) is a non-aqueous titrimetric method and is based on the titration of QTF in glacial acetic acid with 0.01M acetous perchloric acid using crystal violet as indicator. In the second method (method B), QTF has been measured in 0.1M acetic acid spectrophotometrically at a wavelength of 222 nm. The titrimetric method was applicable over the range of 2.0 - 20.0 mg of QTF. The reaction stoichiometry of 1:3 is obtained which served as the basis for calculation. In spectrophotometry, Beer?s law was obeyed over the concentration range of 1.25 - 15.0 ?g mL-1. The linear regression equation of the calibration graph was A = 0.0115 + 0.0673 C with a regression coefficient (r) of 0.9986 (n=7). The apparent molar absorptivity was calculated to be 4.25 ? 104 L mol-1cm-1 and the Sandell sensitivity was 0.0145 ?g cm-2. The limits of detection (LOD) and quantification (LOQ) calculated as per the ICH guidelines were 0.07 and 0.21 ?g mL-1, respectively. Accuracy and precision of the assays were determined by computing the intra-day and inter-day variations at three different levels of QTF. The intra-day and inter-day relative standard deviation (%RSD) were in the range of 0.99 - 2.88 and 1.65 - 2.32%, for method A and method B, respectively, with an acceptable percentage relative error (%RE) < 2%. The methods were successfully applied in the determination of QTF in two different brands of tablets with good accuracy and precision and without detectable interference by excipients. The methods have demonstrated to be simple and easy to apply in routine usage and do not need any costly instrumentation. Therefore, the reported procedures are advantageous and can be adopted in routine quality control laboratories in the developing or under developed countries.

scholarly journals Determination of Residues of Alachlor and Related Herbicides in Crops by Liquid Chromatography with Electrochemical Detection

1997 ◽  
Vol 80 (5) ◽  
pp. 1104-1110 ◽  
Author(s):  
David A Nortrup
Keyword(s):  
Liquid Chromatography ◽  
Steam Distillation ◽  
Solid Phase ◽  
Base Hydrolysis ◽  
Phase Extraction ◽  
Test Portion ◽  
Strong Base ◽  
Relative Standard ◽  
Limit Of Quantitation

Abstract A method is described for determining residues of 3 acetamide herbicidesalachlor [2-chloro-N(2,6- diethylphenyl)-N(methoxymethyl)acetamide], acetochlor [2-chloro-N(2-ethyl-6-methylphenyl)-N (ethoxymethyl)acetamide), and butachlor [2-chloro-N(2,6-diethylphenyl)-N(butoxymethyl)- acetamide)by liquid chromatography (LC). Currently no published method determines metabolites from all 3 herbicides in crops. Strong-base hydrolysis after extraction of a test portion with water-acetonitrile results in the formation of 2,6- diethylaniline (DEA) and 2-(1-hydroxyethyl)-6-ethylaniline from alachlor metabolites, 2-ethyl-6-methylaniline and 2-(1-hydroxyethyl)-6-methylaniline from acetochlor metabolites, and DEA from butachlor. The anilines are isolated by steam distillation, partitioned with Supelclean ENVI-Chrom P solid-phase extraction columns, and methylated prior to LC analysis. The limit of quantitation of aniline moieties is about 0.01 ppm. Recoveries of 0.01- 0.40 ppm aniline moieties are generally 74-103%, with relative standard deviations of 2.2 to 14.0%.

Enantioselective analysis of naproxen using chiral molecular imprinting polymers based thin-layer chromatography

e-Polymers ◽  
2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Fengyun Huangfu ◽  
Bing Wang ◽  
Juanjuan Shan ◽  
Zhiliang Zhang
Keyword(s):  
Particle Size ◽  
Acetic Acid ◽  
Particle Size Distribution ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Size Distribution ◽  
Acid Content ◽  
Rational Design ◽  
Acetic Acid Content ◽  
Layer Chromatography

Abstract This paper describes a rational design and testing of molecularly imprinted polymers (MIPs) as chiral stationary phases of thin-layer chromatography (TLC) for enantiomeric purity of naproxen. Using D-naproxen as template, MIPs with particle size between 10~90 μm were prepared by precipitation polymerization in acetonitrile/methanol mixed solvent. The interactions between functional monomers and template were verified by UV absorption spectrometry. The morphology, particle size distribution and specific surface area of MIPs were also observed by scanning electron microscopy, particle size distribution meter and liquid nitrogen adsorption instrument, respectively. Binding capacities of MIPs had been studied by equilibrium binding assay. Preparation conditions of TLC and impact of acetic acid content on the separation of enantiomers were investigated. The results indicated that when acetic acid content was 4%, the racemates of templates were completely separated, and the chiral separation factor α was 1.58.

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