scholarly journals Determination of N-Acetyl-l-cysteine Ethyl Ester (NACET) by Flow Injection Analysis and Spectrophotometric Detection Using Different Thiol-Sensitive Ligands

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6826
Author(s):  
Lea Kukoc-Modun ◽  
Tomislav Kraljević ◽  
Dimitrios Tsikas ◽  
Njegomir Radić ◽  
Darko Modun
Keyword(s):  
Ethyl Ester ◽  
Flow Injection ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Sampling Rate ◽  
Pharmaceutical Preparations ◽  
Disulfonic Acid ◽  
Range Limit ◽  
Experimental Conditions

A new flow injection spectrophotometric method for the determination of N-acetyl-l-cysteine ethyl ester (NACET) was developed and validated. The method is based on the reduction of Cu(II)-ligand complexes to chromophoric Cu(I)-ligand complexes with the analyte. The studied ligands were neocuproine (NCN), bicinchoninic acid (BCA) and bathocuproine disulfonic acid (BCS). The absorbance of the Cu(I)-ligand complex was measured at 458, 562 and 483 nm for the reactions of NACET with NCN, BCA and BCS, respectively. The method was validated in terms of linear dynamic range, limit of detection and quantitation, accuracy, selectivity, and precision. Experimental conditions were optimized by a univariate method, yielding linear calibration curves in a concentration range from 2.0 × 10−6 mol L−1 to 2.0 × 10−4 mol L−1 using NCN; 2.0 × 10−6 mol L−1 to 1.0 × 10−4 mol L−1 using BCA and 6.0 × 10−7 mol L−1 to 1.2 × 10−4 mol L−1 using BCS. The achieved analytical frequency was 90 h−1 for all three ligands. The method was successfully employed for NACET determination in pharmaceutical preparations, indicating that this FIA method fulfilled all the essential demands for the determination of NACET in quality control laboratories, as it combined low instrument and reagent costs with a high sampling rate.

scholarly journals Optimized and validated flow-injection spectrophotometric analysis of topiramate, piracetam and levetiracetam in pharmaceutical formulations

2011 ◽  
Vol 61 (4) ◽  
pp. 377-389 ◽  
Author(s):  
Ghada Hadad ◽  
Randa Abdel-Salam ◽  
Samy Emara
Keyword(s):  
Flow Injection ◽  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Spectrophotometric Analysis ◽  
Range Limit ◽  
Flow Conditions ◽  
Five Factors ◽  
Rapid Flow

Optimized and validated flow-injection spectrophotometric analysis of topiramate, piracetam and levetiracetam in pharmaceutical formulationsApplication of a sensitive and rapid flow injection analysis (FIA) method for determination of topiramate, piracetam, and levetiracetam in pharmaceutical formulations has been investigated. The method is based on the reaction withortho-phtalaldehyde and 2-mercaptoethanol in a basic buffer and measurement of absorbance at 295 nm under flow conditions. Variables affecting the determination such as sample injection volume, pH, ionic strength, reagent concentrations, flow rate of reagent and other FIA parameters were optimized to produce the most sensitive and reproducible results using a quarter-fraction factorial design, for five factors at two levels. Also, the method has been optimized and fully validated in terms of linearity and range, limit of detection and quantitation, precision, selectivity and accuracy. The method was successfully applied to the analysis of pharmaceutical preparations.

scholarly journals A novel online coupling of ion selective electrode with the flow injection system for the determination of vitamin B1

2016 ◽  
Vol 13 (2) ◽  
pp. 458-469
Author(s):  
Baghdad Science Journal
Keyword(s):  
Flow Injection ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Vitamin B1 ◽  
Pharmaceutical Formulations ◽  
Ion Selective Electrode ◽  
Injection System ◽  
Selective Electrode ◽  
Flow Injection System

A simple, fast, selective of a new flow injection analysis method coupled with potentiometric detection was used to determine vitamin B1 in pharmaceutical formulations via the prepared new selective membranes. Two electrodes were constructed for the determination of vitamin B1 based on the ion-pair vitamin B1-phosphotungestic acid (B1-PTA) in a poly (vinyl chloride) supported with a plasticized di-butyl phthalate (DBPH) and di-butyl phosphate (DBP). Applications of these ion selective electrodes for the determination of vitamin B1 in the pharmaceutical preparations for batch and flow injection systems were described. The ion selective membrane exhibited a near-Nernstian slope values 56.88 and 58.53 mV / decade, with the linear dynamic range of vitamin B1 was 5 x 10-5- 1 x 10-2 and 1 x 10-4-1 x 10-2 mol.L-1, in batch and FIA, respectively. The limit of detection was 3.5 x 10-5 and 9.5 x 10-5 mol.L-1, with the percentage linearity 98.85 and 95.22 in batch and FIA, respectively. The suggested ion selective electrode has been utilized perfection in the determination of vitamin B1 in pharmaceutical formulations using batch and flow injection system, respectively.

scholarly journals Simultaneous Determination of Trace Mefenamic Acid in Pharmaceutical Samples via Flow Injection Fluorometry

2020 ◽  
Vol 10 (03) ◽  
pp. 395-401
Author(s):  
Mohammad K. Hammood ◽  
Maryam Hamed
Keyword(s):  
Flow Injection ◽  
Mefenamic Acid ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Basic Medium ◽  
Minimum Concentration ◽  
Pharmaceutical Samples ◽  
Fluorescence Measurements ◽  
532 Nm

Mefenamic acid belongs to non-steroidal anti-inflammatory drugs that are used widely for the treatment of analgesia. Our aim from this study is to establish a new assay for the quantitative determination of mefenamic acid (MFA) in the pharmaceutical sample by two sensitive and rapid flow injection-fluorometric methods. A homemade fluorometer was used in fluorescence measurements, which using solid-state laser diode 405 and 532 nm as a source, combined with a continuous flow injection technique. The first method depends on the effect of MFA on calcein blue (CLB) fluorescence at 405 nm. Another method is a study of rhodamine-6G (Rh-6G) fluorescence after adding MFA, and recording at 532 nm. Optimum parameters as fluorescent dye concentration, basic medium, flow rate, sample volume, purge time, and delay coil have been investigated. The dynamic range of MFA was 0.2 to 2 mmol.L-1; 0.5 to 2.3 mmol.L-1 with linearity percentage (% r2) 98.92 and 99.83%, for Rh-6G and CLB, respectively. Limit of detection at a minimum concentration in calibration curve 189.34 and 199.89 ng/sample, for Rh-6G and CLB, respectively. The comparison of developed methods with the classical method (UV-vis spectrophotometry) was achieved. The proposed methods were successfully applied for the determination of MFA in the pharmaceutical samples and can be used as an alternative method.

scholarly journals Development of a new analytical spectroscopic methodology based on the competitive aggregation in a dye–surfactant–drug system: Application to the determination of gemfibrozil

2008 ◽  
Vol 22 (4) ◽  
pp. 309-317 ◽  
Author(s):  
Mohammad Amjadi ◽  
Jamshid L. Manzoori ◽  
Leila Farzampour
Keyword(s):  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Calibration Graph ◽  
Experimental Conditions ◽  
Analytical Methodology ◽  
Surfactant Aggregates ◽  
Didodecyldimethylammonium Bromide ◽  
The Difference ◽  
Absorption Features

A new analytical methodology based on the competitive aggregation in a dye–surfactant–drug system is developed for the determination of gemfibrozil. Eriochrome Blue Black R (EBBR) and Didodecyldimethylammonium bromide (DDABr) were the dye and surfactant used, respectively. In the proposed method, the anions of the dye bind to the cationic surfactant molecules to form dye–surfactant aggregates, which are monitored from changes in UV-Vis absorption features of the dye. In the ternary EBBR–DDABr–drug mixtures, the drug competes with the dye to interact with the surfactant, which results in a decrease in dye–surfactant aggregates formation. This, again, causes a change in absorption properties of the dye. The measurement parameter is the difference between the absorption of the dye in the presence and absence of the drug. In the appropriate experimental conditions the absorbance differences are directly proportional to the drug concentration. The influence of several experimental variables such as pH, concentrations of buffer, EBBR and DDABr on the measurement parameter were studied. Under the optimum conditions, the calibration graph was linear up to 6.0 μg ml−1with the correlation coefficient of 0.998. The limit of detection and quantification were found to be 0.044 and 0.15 μg ml−1, respectively. The method was validated and applied to the determination of gemfibrozil in pharmaceutical preparations.

Flow injection spectrofluorimetric determination of iron(III) in water using salicylic acid

2010 ◽  
Vol 64 (4) ◽  
Author(s):  
Adem Asan ◽  
Muberra Andac ◽  
Ibrahim Isildak
Keyword(s):  
Salicylic Acid ◽  
Flow Injection ◽  
Limit Of Detection ◽  
Sampling Rate ◽  
Linear Calibration ◽  
Fluorimetric Determination ◽  
Buffer Solution ◽  
Quenching Effect ◽  
Relative Standard

AbstractA simple and fast flow injection fluorescence quenching method for the determination of iron in water has been developed. Fluorimetric determination is based on the measurement of the quenching effect of iron on salicylic acid fluorescence. An emission peak of salicylic acid in aqueous solution occurs at 409 nm with excitation at 299 nm. The carrier solution used was 2 × 10−6 mol L−1 salicylic acid in 0.1 mol L−1 NH4+/NH3 buffer solution at pH 8.5. Linear calibration was obtained for 5–100 μg L−1 iron(III) and the relative standard deviation was 1.25 % (n = 5) for a 20 μL injection volume iron(III). The limit of detection was 0.3 μg L−1 and the sampling rate was 60 h−1. The effect of interferences from various metals and anions commonly present in water was also studied. The method was successfully applied to the determination of low levels of iron in real samples (river, sea, and spring waters).

Flow Injection Determination of Acetylsalicylic Acid in Pharmaceutical Preparations with an Amperometric Detector

2000 ◽  
Vol 65 (6) ◽  
pp. 954-962 ◽  
Author(s):  
Jorge M. P. J. Garrido ◽  
José L. F. C. Lima ◽  
Cristina D. Matos
Keyword(s):  
Salicylic Acid ◽  
Acetylsalicylic Acid ◽  
Flow Injection ◽  
Sampling Rate ◽  
Hydrolysis Product ◽  
Pharmaceutical Preparations ◽  
Amperometric Detection ◽  
Automated Method ◽  
Pre Treatment

This paper reports on an automated method based on a flow injection analysis single stream system with amperometric detection for the determination of acetylsalicylic acid in pharmaceutical preparations. The amperometric detection is based on the measurement at 0.8 V vs Ag/AgCl of the current generated when the acetylsalicylic acid hydrolysis product, salicylic acid, is oxidised at a glassy carbon electrode. The current produced is directly related to the concentration of the electroactive specie and the salicylic acid content is proportional to the level of acetylsalicylic acid present in the sample, thus it is possible to determine the concentration of acetylsalicylic acid electrochemically. This system allows a sampling rate of 150 samples per hour without requiring any pre-treatment, apart from dissolving them in a NaOH/KCl buffer, pH 13.0. The results obtained were compared with those obtained using reference methods and demonstrated excellent agreement with relative deviation always lower than 2%.

scholarly journals Spectrophotometric Determination of Phenylephrine Hydrochloride in Pharmaceuticals by Flow Injection Analysis Exploiting the Reaction with Potassium Ferricyanide and 4-Aminoantipyrine

2002 ◽  
Vol 85 (4) ◽  
pp. 875-878 ◽  
Author(s):  
José R C Rocha ◽  
Cristiane X Galhardo ◽  
Maria Auxiliadora E Natividade ◽  
Jorge C Masini
Keyword(s):  
Flow Injection ◽  
Flow Injection Analysis ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Condensation Product ◽  
Potassium Ferricyanide ◽  
Linear Dynamic Range ◽  
Phenylephrine Hydrochloride ◽  
Nasal Decongestant

Abstract This paper presents a method for the determination of phenylephrine hydrochloride in pharmaceuticals by spectrophotometric flow injection analysis exploiting the reaction with potassium ferricyanide and 4-aminoantipyrine, which leads to the formation of a condensation product with strong absorptivity at 500 nm. The linear dynamic range was between 0.95 and 9 mg/L, with a limit of detection of 0.2 mg/L and a sampling throughput of 120 samples per hour. The method was applied to eyewashes and nasal decongestant liquid medicines.

Determination of Picogram Levels of Levodopa in Pharmaceutical Preparations and Biofluids by Flow-Injection Chemiluminescence

2014 ◽  
Vol 884-885 ◽  
pp. 566-569 ◽  
Author(s):  
Yun Zhang ◽  
Su Ya Gao
Keyword(s):  
Flow Injection ◽  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Human Saliva ◽  
Quenching Effect ◽  
Dopa Concentration ◽  
Flow Injection Chemiluminescence ◽  
First Time ◽  
Serum And Urine

An ultrasensitive method for determination of L-dopa at picogram levels by flow-injection chemiluminescence (FI-CL) as presented for the first time, based on the quenching effect of levodopa (L-dopa) on the luminol-lysozyme reaction. It was found that the decrement of CL intensity was linearly proportional to the logarithm of L-dopa concentration ranging from 3.0 to 7.0 × 103pg mL-1(R= 0.9967), with the limit of detection (LOD) of 1.0 pg mL-1(3σ). The proposed procedure was successfully applied to the determination of L-dopa in pharmaceutical preparations, human saliva, serum, and urine samples with the recoveries ranging from 96.7% to 104.3% and RSDs less than 4.0% (n= 5).

scholarly journals Flow Injection Spectrophotometric Determination of Thymol using 4-Aminoantipyrine and Copper(II) Nitrate

2015 ◽  
Vol 12 (2) ◽  
pp. 332-339
Author(s):  
Baghdad Science Journal
Keyword(s):  
Flow Injection ◽  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Coupling Reaction ◽  
Copper Nitrate ◽  
Calibration Graph ◽  
Limit Of Quantification ◽  
Accuracy And Precision ◽  
Mouth Wash

Flow-injection (FI) spectrophotometric method has been developed for the analysis of thymol in pharmaceutical preparations. The method is based on organic coupling reaction between thymol and 4-amino antipyrine in the presence of alkaline medium to form an intense stable red color complex with copper nitrate that has a maximum absorption at 490 nm. Optimum conditions for determination of the drug was investigated .The calibration graph was linear over the range of 5-500 µg.ml-1 of thymol . The limit of detection (LOD) and limit of quantification (LOQ) were 1.81 ?g mL-1 and 3.60 ?g mL-1 respectively .The proposed method was applied satisfactorily to the determination of thymol in mouth wash preparations. The procedure is characterized by its simplicity, accuracy and precision.

Optimum HPLC Conditions for Determination of Dibucaine HCL, Fluocortolone Pivalate and Fluocortolone Caproate by Using Experimental Design

2018 ◽  
Vol 15 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Bürge Aşçı ◽  
Mesut Koç
Keyword(s):  
Experimental Design ◽  
Flow Rate ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Acid Mixture ◽  
Solution Stability ◽  
Uv Detector

Introduction:This paper presents the development and validation of a novel, fast, sensitive and accurate high performance liquid chromatography (HPLC) method for the simultaneous quantitative determination of dibucaine HCl, fluocortolone pivalate and fluocortolone caproate in pharmaceutical preparations.Experiment:Development of the chromatographic method was based on an experimental design approach. A five-level-three-factor central composite design requiring 20 experiments in this optimization study was performed in order to evaluate the effects of three independent variances including mobile phase ratio, flow rate and amount of acid in the mobile phase.Conclusion:The optimum composition for mobile phase was found as a methanol:water:acetic acid mixture at 71.6 : 26.4 : 2 (v/v/v) ratio and optimum separation was acquired by isocratic elution with a flow rate of 1.3 mL/min. The analytes were detected using a UV detector at 240 nm. The developed method was validated in terms of linearity, precision, accuracy, limit of detection/quantitation and solution stability and successfully applied to the determination of dibucaine HCl, fluocortolone pivalate and fluocortolone caproate in pharmaceutical topical formulations such as suppositories and ointments.

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