scholarly journals Voltammetric Determination of Captopril Using Chlorpromazine as a Homogeneous Mediator

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Hossein Bahramipur ◽  
Fahimeh Jalali
Keyword(s):  
Electron Transfer ◽  
Limit Of Detection ◽  
Linear Sweep Voltammetry ◽  
Pharmaceutical Formulations ◽  
Electron Transfer Reaction ◽  
Linear Calibration ◽  
Serum Samples ◽  
Catalytic Rate Constant ◽  
Relative Standard

Chlorpromazine was used as a homogeneous electrocatalyst in the oxidation of captopril. The anodic peak current of chlorpromazine was increased substantially in the presence of low concentrations of captopril (pH 4). Cyclic voltammetry and chronoamperometry were used to study the kinetics of the catalytic electron transfer reaction. The values of electron transfer coefficient () and catalytic rate constant () were estimated to be 0.34 and , respectively. Linear sweep voltammetry was used for the determination of captopril in the presence of chlorpromazine. A linear calibration curve was obtained in the concentration range of captopril of 10.0–300.0 μM, with a limit of detection of 3.65 μM. The relative standard deviation (RSD%) for 5 replicate measurements of captopril (100 μM) was 1.96%. The method was applied to the determination of captopril in pharmaceutical formulations and blood serum samples with satisfactory results.

scholarly journals Determination of Tianeptine in Tablets by High-Performance Liquid Chromatography with Fluorescence Detection

2007 ◽  
Vol 90 (3) ◽  
pp. 720-724
Author(s):  
Sevgi Tatar Ulu
Keyword(s):  
Lower Limit ◽  
High Performance ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Linear Calibration ◽  
Fluorescence Detector ◽  
Relative Standard ◽  
Validation Parameters ◽  
Limit Of Quantitation

Abstract A sensitive and selective high-performance liquid chromatographic method has been developed for the determination of tianeptine (Tia) in tablets. The method is based on derivatization of Tia with 4-chloro-7-nitrobenzofurazan (NBD-Cl). A mobile phase consisting of acetonitrile10 mM orthophosphoric acid (pH 2.5; 77 + 23) was used at a flow rate of 1 mL/min on a C18 column. The Tia-NBD derivative was monitored using a fluorescence detector, with emission set at 520 nm and excitation at 458 nm. Gabapentin was selected as an internal standard. Linear calibration graphs were obtained in the concentration range of 45300 ng/mL. The lower limit of detection (LOD) was 10 ng/mL at a signal-to-noise ratio of 4. The lower limit of quantitation (LOQ) was 45 ng/mL. The relative standard values for intra- and interday precision were <0.46 and <0.57%, respectively. The recovery of the drug samples ranged between 98.89 and 99.85%. No chromatographic interference from the tablet excipients was found. The proposed method was validated in terms of precision, robustness, recovery, LOD, and LOQ. All the validation parameters were within the acceptance range. The proposed method was applied for the determination of Tia in commercially available tablets. The results were compared with those obtained by an ultraviolet spectrophotometric method using t- and F-tests.

scholarly journals DEVELOPMENT AND VALIDATION OF ULTRAVIOLET-SPECTROPHOTOMETRIC METHOD FOR DETERMINATION OF FEBUXOSTAT FOR CONDUCTING IN-VITRO QUALITY CONTROL TESTS IN BULK AND PHARMACEUTICAL DOSAGE FORMS

2018 ◽  
Vol 11 (9) ◽  
pp. 115
Author(s):  
Jaspreet Kaur ◽  
Daljit Kaur ◽  
Sukhmeet Singh
Keyword(s):  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Dosage Forms ◽  
Pharmaceutical Dosage Forms ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Development And Validation

Objective: A simple, accurate, and selective ultraviolet-spectrophotometric method has been developed for the estimation of febuxostat in the bulk and pharmaceutical dosage forms.Method: The method was developed and validated according to International Conference on Harmonization (ICH Q2 R1) guidelines. The developed method was validated statistically with respect to linearity, range, precision, accuracy, ruggedness, limit of detection (LOD), limit of quantitation (LOQ), and recovery. Specificity of the method was demonstrated by applying different stressed conditions to drug samples such as acid hydrolysis, alkaline hydrolysis, oxidative, photolytic, and thermal degradation.Results: The study was conducted using phosphate buffer pH 6.8 and λmax was found to be 312 nm. Standard plot having a concentration range of 1–10 μg/ml showed a good linear relationship with R2=0.999. The LOD and LOQ were found to be 0.118 μg/ml and 0.595 μg/ml, respectively. Recovery and percentage relative standard deviations were found to be 100.157±0.332% and <2%, respectively.Conclusion: Proposed method was successfully applicable to the pharmaceutical formulations containing febuxostat. Thus, the developed method is found to be simple, sensitive, accurate, precise, reproducible, and economical for the determination of febuxostat in pharmaceutical dosage forms.

scholarly journals Sensitive Determination of Terazosin in Pharmaceutical Formulations and Biological Samples by Ionic-Liquid Microextraction Prior to Spectrofluorimetry

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Mohsen Zeeb ◽  
Mahdi Sadeghi
Keyword(s):  
Ionic Liquid ◽  
Ionic Strength ◽  
Biological Samples ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Experimental Conditions ◽  
Relative Standard ◽  
Common Ion ◽  
Liquid Microextraction

An efficient and environmentally friendly sample preparation method based on the application of hydrophobic 1-Hexylpyridinium hexafluorophosphate [Hpy][PF6] ionic liquid (IL) as a microextraction solvent was proposed to preconcentrate terazosin. The performance of the microextraction method was improved by introducing a common ion of pyridinium IL into the sample solution. Due to the presence of the common ion, the solubility of IL significantly decreased. As a result, the phase separation successfully occurred even at high ionic strength, and the volume of the settled IL-phase was not influenced by variations in the ionic strength (up to 30% w/v). After preconcentration step, the enriched phase was introduced to the spectrofluorimeter for the determination of terazosin. The obtained results revealed that this system did not suffer from the limitations of that in conventional ionic-liquid microextraction. Under optimum experimental conditions, the proposed method provided a limit of detection (LOD) of 0.027 μg L−1and a relative standard deviation (R.S.D.) of 2.4%. The present method was successfully applied to terazosin determination in actual pharmaceutical formulations and biological samples. Considering the large variety of ionic liquids, the proposed microextraction method earns many merits, and will present a wide application in the future.

scholarly journals A Terbium Sensitized Luminescence Method for the Assay of Flubiprofen in Pharmaceutical Formulations

2014 ◽  
Vol 19 (1) ◽  
pp. 54
Author(s):  
Salma M.Z. Al-Kindy ◽  
Arwa Al-Ghazali ◽  
Fakhr Eldin O. Suliman ◽  
Haidar A.J. Al-Lawati
Keyword(s):  
Limit Of Detection ◽  
Tap Water ◽  
Pharmaceutical Formulations ◽  
Aqueous System ◽  
Tween 20 ◽  
Luminescence Method ◽  
Time Resolved ◽  
Relative Standard ◽  
Excellent Reproducibility

A sensitive time-resolved luminescence method for the determination of flubiprofen (FLP) in methanol and in aqueous solution is described. The method is based on the luminescence sensitization of terbium (Tb3+ ) by the formation of a ternary complex with FLP in the presence of 4,7 diphenyl 1,10 phenanthroline (DPP) as co-ligand, and Tween-20 as surfactant. The signal for Tb-FLP-DPP was monitored at λex  = 285 nm and λem  = 552 nm. Optimum conditions for the formation of the complex in an aqueous system were TRIS buffer, pH 8.0, DPP (2.5Å~10−7  M), Tween-20 (0.30%) and 4Å~10-5  mol L-1  of Tb3+  which allowed the determination of 20–1000 ng mL-1  of FLP with a limit of detection (LOD) of 10 ng mL-1 . The relative standard deviations of the method ranged between 0.6 and 1.4% indicating excellent reproducibility of the method. The proposed method was successfully applied for the assays of FLP in pharmaceutical formulations and spiked tap water samples with average recoveries of 87% – 95%. 

scholarly journals Rapid, Simple, and Sensitive Spectrofluorimetric Method for the Estimation of Ganciclovir in Bulk and Pharmaceutical Formulations

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Garima Balwani ◽  
Emil Joseph ◽  
Satish Reddi ◽  
Vibhu Nagpal ◽  
Ranendra N. Saha
Keyword(s):  
Standard Deviation ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Calibration Graph ◽  
Limit Of Quantification ◽  
Average Percentage ◽  
Ich Guidelines ◽  
Spectrofluorimetric Method ◽  
Relative Standard

A new, simple, rapid, sensitive, accurate, and affordable spectrofluorimetric method was developed and validated for the estimation of ganciclovir in bulk as well as in marketed formulations. The method was based on measuring the native fluorescence of ganciclovir in 0.2 M hydrochloric acid buffer of pH 1.2 at 374 nm after excitation at 257 nm. The calibration graph was found to be rectilinear in the concentration range of 0.25–2.00 μg mL−1. The limit of quantification and limit of detection were found to be 0.029 μg mL−1and 0.010μg mL−1, respectively. The method was fully validated for various parameters according to ICH guidelines. The results demonstrated that the procedure is accurate, precise, and reproducible (relative standard deviation <2%) and can be successfully applied for the determination of ganciclovir in its commercial capsules with average percentage recovery of 101.31 ± 0.90.

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).

scholarly journals Simultaneous Determination of Aspirin and Rosuvastatin Calcium in Capsules by Using RP-HPLC Coupled with Photo Diode Array Detection

2014 ◽  
Vol 33 ◽  
pp. 218-230
Author(s):  
Ankita Panchal ◽  
Gaurav Sanghvi ◽  
Ashish Vachhani ◽  
Navin Sheth ◽  
Devendra Vaishnav
Keyword(s):  
Quality Control ◽  
Simultaneous Determination ◽  
Lower Limit ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Coefficient Of Determination ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
Rosuvastatin Calcium

A simple, sensitive, specific, and cost effective method for simultaneous determination of Aspirin and Rosuvastatin calcium was developed and validated in single dosage formulation. The sample solution of ASP and RSTC was prepared using methanol as a solvent. Separation of ASP and RSTC was achieved with a mobile phase consisting of 20 mM KH2PO4 : Methanol (30:70 v/v) at a flow rate of 1.0 ml/min. Separations were performed on Merck hibar 250-4.6 RP18 (5 µm) column (150 mm X 3.0 mm), using a Shimadzu Prominence HPLC system equipped with a Shimadzu SPD-20A detector, Rhenodyne 7725i injector with 20 μL loop, LC-20 AD pump, CBM-20 Alite controller and LC Solution software. Retention times of ASP and RSTC were 3.747 and 5.969 minutes respectively. Absolute recovery of ASP and RSTC was 100.3 and 100.03 % respectively. The lower limit of quantification (LLOQ) of ASP and RSTC was 0.3097 and 0.1063 ppm and lower limit of detection (LLOD) of ASP and RSTC was 0.01535 and 0.01358 ppm respectively. Linearity was established for the range of concentrations 15.00-90.0 μg/ml and 2.0-12.0 μg/ml for ASP and RSTC respectively with the coefficient of determination (R2) of 0.994 and 0.999 for both the compounds. The inter- and intra-day precision in the measurement of ASP quality control (QC) sample 75 μg/ml, were in the range 0.1-0.2 % relative standard deviation (R.S.D.) and 0.2-0.3 % R.S.D., respectively. The inter- and intra-day precision in the measurement of RST quality control (QC) sample 10 μg/ml, were in the range 0.1-0.2 % R.S.D., and 0.0-0.3 % R.S.D., respectively. The developed method would be applicable for routine quality control of ASP And RSTC in bulk as well as in pharmaceutical formulations

scholarly journals Voltammetric Determination of Uric Acid in Clinical Serum Samples Using DMF Modified Screen Printed Carbon Electrodes

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Melaku Metto ◽  
Samrawit Eramias ◽  
Bekele Gelagay ◽  
Alemayehu P. Washe
Keyword(s):  
Uric Acid ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Clinical Samples ◽  
Carbon Electrodes ◽  
Current Response ◽  
Serum Samples ◽  
Relative Standard ◽  
Screen Printed

Screen printed carbon electrodes (SPCEs) provide attractive opportunity for sensitive and selective determination target analytes in clinical samples. The aim of the current work was to develop SPCEs based sensor for the determination of uric acid in clinical serum samples. The electrodes were pretreated by soaking in N,N-dimethylformamide for 5 minutes followed by drying in an oven at 100°C for 20 mins. The effect of surface pretreatment was characterized using cyclic voltammetry. The current response of uric acid detection was improved by a factor of 3.5 in differential pulse voltammetric measurement compared to unmodified electrode. Under the optimized conditions, the sensor displayed two dynamic linear ranges 5-100 μM and 100-500 μM with correlation coefficient, R2, values of 0.98782 and 0.97876, respectively. The limit of detection and limit of quantification calculated using the dynamic linear range 5-100 μM were 1.9 x 10−7 M and 6.33 x 10−7 M, respectively. The developed sensor displayed well separated and discerned peaks for UA in presence of the potential interferent (ascorbic acid and citric acid). The electrode was successfully applied for the detection of very low level of UA in clinical serum samples in a phosphate buffer solution (pH = 7). The proposed sensor showed a very high reproducibility and repeatability with the relative standard deviation of 0.9%. In conclusion, a simple and low cost sensor based on SPCEs is developed for sensitive and selective detection of uric acid in clinical samples.

scholarly journals Direct Spectrophotometric Determination of Glimepiride in Pure Form And Pharmaceutical Formulations Using Bromocresol Purple

2018 ◽  
Vol 15 (2) ◽  
pp. 6186-6198
Author(s):  
Abdul Aziz Ramadan ◽  
Souad Zeino
Keyword(s):  
Limit Of Detection ◽  
Reference Method ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Bromocresol Purple ◽  
Reaction Conditions ◽  
Reagent Blank ◽  
Limit Of Quantification ◽  
Relative Standard

A simple, direct and accurate spectrophotometric method has been developed for the determination of Glimepiride (GLM) in pure and pharmaceutical formulations by complex formation with bromocresol purple (BCP). The method involves the formation of a yellow ion-pair complex between BCP with glimepiride at pH<3,8; after reacting GLM with Na2CO3 to give C24H33N4H+O5NaS which is extracted by chloroform. The formed complex [GLM]:[ BCP] was measured at lmax 418 nm against the reagent blank prepared in the same manner. Variables were studied in order to optimize the reaction conditions. Molar absorptivity (e) for complex was  20600  L.mol-1.cm-1. Beer’s law was obeyed in the concentration range of  1.226 – 46.608   mg.mL-1 in present of 5.0x10-4 mol/l of BCP with good correlation coefficient (R2= 0.9997). The relative standard deviation did not exceed 3.6%. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.15 and 0.46 mg.mL-1, respectively. The proposed method was validated for specificity, linearity, precision and accuracy, repeatability, sensitivity (LOD and LOQ)  and robustness. The developed method is applicable for the determination of GLM in  pure and different dosage forms with average assay of 98.8 to 102.0% and the results are in good agreement with those obtained by the  RP-HPLC reference method.  

scholarly journals Development of sensitive and accurate solid-phase microextraction procedure for preconcentration of As(III) ions in real samples

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adil Elik ◽  
Mustafa Tuzen ◽  
Baki Hazer ◽  
Savaş Kaya ◽  
K. P. Katin ◽  
...  
Keyword(s):  
Trace Amount ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Hydride Generation ◽  
Absorption Spectrometry ◽  
Linear Calibration ◽  
Nuclear Magnetic Resonance Spectrometer ◽  
Relative Standard ◽  
Infrared Spectrometer

AbstractWe synthesized the poly(methyl methacrylate-co-2-aminoethyl methacrylate (PMaema) amphiphilic copolymer in a form of solid phase adsorbent. Then it was used for separation, preconcentration and determination of trace amount of As(III) ions from foods and waters with hydride generation atomic absorption spectrometry. The PMaema was characterized by fourier transform infrared spectrometer and nuclear magnetic resonance spectrometer. The adsorption of As(III) to the PMaema was also supported using computational chemistry studies. The experimental parameters (pH, PMaema amount, adsorption time and ethanol volume) were optimized using a three-level Box–Behnken design with four experimental factors. We observed linear calibration curve for the PMaema amount in the 10–500 ng L−1 range (R2 = 0.9956). Limit of detection, preconcentration factor and sorbent capacity of PMaema were equal to 3.3 ng L−1, 100 and 75.8 mg g−1, respectively. The average recoveries (spiked at 50 ng L−1) changes in the range of 91.5–98.6% with acceptable relative standard deviation less than 4.3%. After validation studies, the method was successfully applied for separation, preconcentration and determination of trace amount of As(III) from foods and waters.

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