scholarly journals Fast Determination of Auramine O in Food by Adsorptive Stripping Voltammetry

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Thuong Nguyen Thi Kim ◽  
Thi Thu Bui ◽  
Anh Tuan Pham ◽  
Van Thang Duong ◽  
Thi Huong Giang Le
Keyword(s):  
Limit Of Detection ◽  
Electrochemical Behaviour ◽  
Pulse Amplitude ◽  
Reduction Peak ◽  
Hanging Mercury Drop Electrode ◽  
Experimental Conditions ◽  
Mercury Drop Electrode ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Auramine O

The electrochemical behaviour of auramine O on the hanging mercury drop electrode has been investigated by cyclic and square wave voltammetry method. Reduction peak of auramine O was irreversible and adsorptive on the hanging mercury drop electrode. The optimal conditions were chosen to be Briton–Robinson buffer pH 9.0, accumulation potential −0.5 V vs. Ag/AgCl/KCl, accumulation time 60 s, pulse amplitude 250 mV·s−1, and frequency 50 Hz. At the optimum experimental conditions, the peak of the target analyte was sharp and asymmetric. The linearity of the peak current depending on the concentration ranged from 4.0 × 10−8 to 6.4 × 10−7 mol L−1. The limit of detection and limit of quantitation were 2.46 × 10−8 mol L−1 and 8.21 × 10−8 mol L−1, respectively. The recovery and relative standard deviation were 94.9% and 2.0% (n = 5). The developed method was successfully applied to determine auramine O in chicken samples with an appropriate sample preparation.

scholarly journals Spectrofluorimetric determination of amlodipine in human plasma without derivatization

2012 ◽  
Vol 48 (4) ◽  
pp. 719-725 ◽  
Author(s):  
Yucel Kadioglu ◽  
Murat Ozturk
Keyword(s):  
Channel Blocker ◽  
Limit Of Detection ◽  
Plasma Samples ◽  
Experimental Conditions ◽  
Spectrofluorimetric Method ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Spectrofluorimetric Determination ◽  
Better Than

A rapid and sensitive spectrofluorimetric method was developed for the determination of amlodipine (AD), a calcium channel blocker, in the plasma. The type of solvent, the wavelength range, and the range of AD concentration were selected to optimize the experimental conditions. The calibration curves were linear (r² >0.997) in the concentration range of 0.1-12.5 ppm of AD. The limit of quantitation and limit of detection values for the method for plasma samples were 0.1 ppm and 0.07 ppm, respectively. The precision calculated as the relative standard deviation was less than 3.5%, and the accuracy (relative error) was better than 5.5% (n=6). The method developed in this study can be directly and easily applied for the determination of AD in the plasma without derivatization in plasma.

scholarly journals Determination of Lead Desorption from G. fisheri Seaweed Using Edible Eluents by Voltammetry at the Hanging Mercury Drop Electrode

2016 ◽  
Vol 855 ◽  
pp. 3-8 ◽  
Author(s):  
Charuwan Khamkaew ◽  
Sontaya Manaboot
Keyword(s):  
Deposition Time ◽  
Ethylenediaminetetraacetic Acid ◽  
Limit Of Detection ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Hanging Mercury Drop Electrode ◽  
Mercury Drop Electrode ◽  
Desorption Efficiency ◽  
Relative Standard

A simple, rapid, selective and sensitivity approach for the determination of Pb(II) in G. fisheri seaweed is described. The method is based on differential pulse anodic stripping voltammetry (DPASV) at hanging mercury drop electrode (HMDE) vs. Ag/AgCl in 0.2 M ammonium acetate (NH4OAc) pH 7.5. The operating analytical conditions; deposition potential (Edep) of -0.4 V, peak potential of -0.78 V, and mercury dropped size of 3 were performed. To see the sensitivity of Pb(II) measurement, the influences of deposition time and stirring speed were investigated. From the findings, the optimal parameters; deposition time of 90 s, and stirring speed of 2000 rpm were obtained. In these conditions, the limit of detection (3σ) of 0.60 µgL-1 and the linear range extended to 12.50 µgL-1 (r2=0.9999) were obtained. The relative standard deviation (RSD) of triplicate measurements using 1.8 µgL-1 of Pb(II) was 1.22%. The method was then applied to measure Pb(II) in real samples. In this study, the desorption efficiency of edible eluents by batch method was determined. The method is based on Pb(II) desorption using different types of edible eluents; acetic acid (HOAc), citric acid (CTA), sodium chloride (NaCl), sodium bicarbonate (NaHCO3), ethylenediaminetetraacetic acid (EDTA), and chitosan (CTS). Batch desorption of Pb(II) from seaweed soaked in individual eluent was performed by shaking at 100 rpm for 2 h at ambient temperature. Results show that the most effective eluent in desorbing the contaminated Pb(II) from G. fisheri with up to 82% of desorption efficiency for bound Pb(II) was EDTA solution.

scholarly journals Anodic Stripping Voltammetry with the Hanging Mercury Drop Electrode for Trace Metal Detection in Soil Samples

Chemosensors ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 107
Author(s):  
Kequan Xu ◽  
Clara Pérez-Ràfols ◽  
Amine Marchoud ◽  
María Cuartero ◽  
Gastón A. Crespo
Keyword(s):  
Metal Ions ◽  
Limit Of Detection ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Hanging Mercury Drop Electrode ◽  
Mercury Drop Electrode ◽  
Redox Active ◽  
Active Metal ◽  
Metal Detection ◽  
Trace Metal Detection

The widely spread use of the hanging mercury drop electrode (HMDE) for multi-ion analysis is primarily ascribed to the following reasons: (i) excellent reproducibility owing to the easy renewal of the electrode surface avoiding any hysteresis effect (i.e., a new identical drop is generated for each measurement to be accomplished); (ii) a wide cathodic potential window originating from the passive hydrogen evolution and solvent electrolysis; (iii) the ability to form amalgams with many redox-active metal ions; and (iv) the achievement of (sub)nanomolar limits of detection. On the other hand, the main controversy of the HMDE usage is the high toxicity level of mercury, which has motivated the scientific community to question whether the HMDE deserves to continue being used despite its unique capability for multi-metal detection. In this work, the simultaneous determination of Zn2+, Cd2+, Pb2+, and Cu2+ using the HMDE is investigated as a model system to evaluate the main features of the technique. The analytical benefits of the HMDE in terms of linear range of response, reproducibility, limit of detection, proximity to ideal redox behavior of metal ions and analysis time are herein demonstrated and compared to other electrodes proposed in the literature as less-toxic alternatives to the HMDE. The results have revealed that the HMDE is largely superior to other reported methods in several aspects and, moreover, it displays excellent accuracy when simultaneously analyzing Zn2+, Cd2+, Pb2+, and Cu2+ in such a complex matrix as digested soils. Yet, more efforts are required towards the definitive replacement of the HMDE in the electroanalysis field, despite the elegant approaches already reported in the literature.

Rapid and Sensitive Liquid Chromatographic Method for Determination of Anastrozole in Different Polymer–Lipid Hybrid Nanoparticles

2021 ◽  
pp. 247263032098230
Author(s):  
Dilshad Ahmad ◽  
Faisal A. Al Meshaiti ◽  
Yazeed K. Al Anazi ◽  
Osama Al Owassil ◽  
Alaa Eldeen B. Yassin
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Reversed Phase ◽  
Hplc Method ◽  
Hybrid Nanoparticles ◽  
Array Detector ◽  
Relative Standard ◽  
Validation Parameters ◽  
Limit Of Quantitation ◽  
Inhibitor Drug

Anastrozole, an aromatase inhibitor drug, is used for the treatment of breast cancer in pre- and postmenopausal women. Anastrozole’s incorporation into nanoparticulate carriers would enhance its therapeutic performance. To perceive the exact loaded amount of drug in nanocarriers, a valid analytical method is required. The reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated by using the C18 column, 150 × 4.6 mm, 5 µm particle size, in isocratic mobile phase composed of 50:50 V/V (volume/volume) acetonitrile–phosphate buffer (pH 3) flowing at a rate of 1.0 mL/min, and a diode array detector (DAD) set at λmax = 215 nm. The validation parameters such as linearity, accuracy, specificity, precision, and robustness have proven the accuracy of the method, with the relative standard deviation percentage (% RSD) values < 2. The limit of detection of the method was found equal to 0.0150 µg/mL, and the limit of quantitation was 0.0607 µg/mL. The percent recovery of sample was in the range of 98.04–99.25%. The method has the advantage of being rapid with a drug retention time of 2.767 min, specific in terms of resolution of peaks void of interference with any of the excipients, and high reproducibility. This makes it highly applicable for quality control purposes.

scholarly journals Determination of cobalt in water samples by atomic absorption spectrometry after pre-concentration with a simple ionic liquid-based dispersive liquid-liquid micro-extraction methodology

2010 ◽  
Vol 8 (3) ◽  
pp. 617-625 ◽  
Author(s):  
Hossein Abdolmohammad-Zadeh ◽  
Elnaz Ebrahimzadeh
Keyword(s):  
Ionic Liquid ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Water Samples ◽  
Limit Of Detection ◽  
Absorption Spectrometry ◽  
Experimental Conditions ◽  
Flame Atomic Absorption ◽  
Relative Standard

AbstractA rapid dispersive liquid-liquid micro-extraction (DLLME) methodology based on the application of 1-hexylpyridinium hexafluorophosphate [C6py][PF6] ionic liquid (IL) as an extractant solvent was applied for the pre-concentration of trace levels of cobalt prior to determination by flame atomic absorption spectrometry (FAAS). 1-Phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) was employed as a chelator forming a Co-PMBP complex to extract cobalt ions from aqueous solution into the fine droplets of [C6py][PF6]. Some effective factors that influence the micro-extraction efficiency include the pH, the PMBP concentration, the amount of ionic liquid, the ionic strength, the temperature and the centrifugation time which were investigated and optimized. In the optimum experimental conditions, the limit of detection (3s) and the enrichment factor were 0.70 µg L−1 and 60, respectively. The relative standard deviation (RSD) for six replicate determinations of 50 µg L−1 Co was 2.36%. The calibration graph using the pre-concentration system was linear at levels 2–166 µg L−1 with a correlation coefficient of 0.9982. The applicability of the proposed method was evaluated by the determination of trace amounts of cobalt in several water samples.

Simultaneous Determination of Four Herbicide and Pesticide Residues in Chinese Green Tea Using QuEChERS Purification Procedure and UPLC-MS/MS Analysis

2013 ◽  
Vol 634-638 ◽  
pp. 1586-1590
Author(s):  
Su Fang Wang ◽  
Shou Jie Zhang ◽  
Chun Hong Dong ◽  
Guo Qing Wang ◽  
Jun Feng Guo ◽  
...  
Keyword(s):  
Formic Acid ◽  
Simultaneous Determination ◽  
Green Tea ◽  
Limit Of Detection ◽  
Multiple Reaction Monitoring ◽  
Graphitized Carbon Black ◽  
Ms Analysis ◽  
Relative Standard ◽  
Limit Of Quantitation

A method for simultaneous determination of residuals of four herbicides and pesticides, simazine, carboxin, diflubenzuron and rotenone, in Chinese green tea was developed. In the proposed method, the tea powder was placed in a centrifuge tube with a plug, extracted in saturated aqueous sodium chloride solution and acetonitrile, agitated using vortex oscillator, and then centrifuged 5 min at 4000 rpm. The supernatant solution was purified by primary secondary amine (PSA) sorbent, C18 power, and graphitized carbon black powder, respectively. Then the purified extracts were dissolved with acetonitrile:0.1% formic acid aqueous solution (40:60, V/V) and agitated, filtered using a syringe with 0.22 μm nylon filter prior to UPLC-MS/MS analysis. The UPLC analysis was performed on an ACQUITY UPLC® HSS T3 column (2.1 mm×100 mm, 1.8 µm), using acetonitrile-0.1% formic acid as mobile phase with the flow rate as 0.3 mL•min-1. Injection volume was 10 µL. Positive ionization mode was applied, and the ions were monitored in the multiple reaction monitoring (MRM) mode with curtain gas 0.069 MPa, collision gas 0.052 MPa, ESI ion spray voltage 5000 V, temperature 550 °C, nebulizer gas 0.24 MPa, and turbo gas 0.28 MPa. The limit of detection (LOD) and limit of quantitation (LOQ) of the proposed method are 1 μg•kg-1and 5 μg•kg-1, respectively. The average recoveries of the four pesticides at 10, 20, and 50 µg•kg-1spiking levels range from 77.4% to 95.3%. TheSupersSuperscript textcript textrelative standard deviation (RSD) (n=6) range form 11.83% to 4.52%.

scholarly journals Development and Application of an UHPLC-MS/MS Method for Comparative Pharmacokinetic Study of Eight Major Bioactive Components from Yin Chen Hao Tang in Normal and Acute Liver Injured Rats

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yun Wang ◽  
Xinrui Xing ◽  
Yan Cao ◽  
Liang Zhao ◽  
Sen Sun ◽  
...  
Keyword(s):  
Lower Limit ◽  
Limit Of Detection ◽  
Injury Model ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Liquid Chromatography Tandem Mass ◽  
Bioactive Ingredients ◽  
Aloe Emodin ◽  
Plasma Pharmacokinetics ◽  
Ultrahigh Performance Liquid Chromatography

Yin Chen Hao Tang (YCHT) is one of the most famous hepatoprotective herbal formulas in China, but its pharmacokinetic investigation in model rats has been rarely conducted. In this study, the hepatic injury model was caused by intraperitoneal injections of carbon tetrachloride (CCl4), and YCHT was orally administered to the model and normal rats. An ultrahigh performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) method was established to analyze the plasma pharmacokinetics of eight major bioactive ingredients from YCHT in both the normal and liver injured rats. The calibration curves presented good linearity (r > 0.9981) in the concentration range. The relative standard deviation (RSD%) of inter- and intraday precision was within 9.55%, and the accuracy (RE%) ranged from -10.72% to 2.46%. The extraction recovery, matrix effect, and stability were demonstrated to be within acceptable ranges. The lower limit of detection (LLOD) and lower limit of quantitation (LLOQ) were around 0.1 ng/mL and 0.5 ng/mL, respectively, which were much lower than those in other related researches. Results reveal that there are significant differences in the pharmacokinetics of scoparone, geniposide, rhein, aloe-emodin, physcion, and chrysophanol in hepatic injured rats as compared to those in control except for scopoletin and emodin. Our experimental results provide a meaningful reference for the clinical dosage of YCHT in treating liver disorders, and the improvement of LLOD and LLOQ can also broaden the range of our method’s application, which is very suitable for quantitating these eight compounds with low levels.

scholarly journals SENSITIVE DETERMINATION OF RELATED SUBSTANCES IN PIOGLITAZONE HYDROCHLORIDE BY HPLC

2017 ◽  
Vol 9 (2) ◽  
pp. 34
Author(s):  
N. Balaji ◽  
Sayeeda Sultana
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Internal Diameter ◽  
Related Substances ◽  
Relative Standard ◽  
Limit Of Quantitation

Objective: An efficient, high performance liquid chromatographic method has been developed and validated for the quantification of related substances in pioglitazone hydrochloride drug substance.Methods: This method includes the determination of three related substances in pioglitazone hydrochloride. The mobile phase A is 0.1% w/v triethylamine in water with pH 2.5 adjusted by dilute phosphoric acid. The mobile phase B is premixed and degassed mixtures of acetonitrile and methanol. The flow rate was 1 ml/min. The elution used was gradient mode. The HPLC column used for the analysis was symmetry C18 with a length of 250 mm, the internal diameter of 4.6 mm and particle size of 5.0 microns.Results: The developed method was found to be linear with the range of 0.006-250% with a coefficient of correlation 0.99. The precision study revealed that the percentage relative standard deviation was within the acceptable limit. The limit of detection and limit of quantitation of the impurities was less than 0.002%and 0.006% with respect to pioglitazone hydrochloride test concentration of 2000 µg/ml respectively. This method has been validated as per ICH guidelines Q2 (R1).Conclusion: A reliable, economical HPLC method was magnificently established for quantitative analysis of related substances of pioglitazone hydrochloride drug substance.

scholarly journals Application of Fourier Transform Infrared Spectrophotometry Method for Analysis of Metformin Hydrochloride in Marketed Tablet Dosage Form

2021 ◽  
Vol 7 (2) ◽  
pp. 168-177
Author(s):  
Nerdy Nerdy ◽  
Linda Margata ◽  
Dian Ika Perbina Meliala ◽  
Bunga Mari Sembiring ◽  
Selamat Ginting ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Dosage Form ◽  
Limit Of Detection ◽  
Fourier Transform Infrared ◽  
Metformin Hydrochloride ◽  
Infrared Spectrophotometry ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
The Fourier Transform ◽  
Tablet Dosage

The first line drug given for monotherapy for diabetes mellitus type 2 is metformin hydrochloride, which is a biguanide antihyperglycemic drug. The aim of this research was to develop, validate, and apply the Fourier Transform Infrared spectrophotometry method to identify and determine metformin hydrochloride in marketed tablet dosage form. This research included preparation of standard, analysis of samples, and validation of method. The specific wavenumber obtained for qualitative analysis was 1645.68 cm–1 and 1574.8 cm–1. The specific area obtained for quantitative analysis with a single baseline ranged from 1701.53 cm–1 to 1535.66 cm–1. All metformin hydrochloride marketed tablet dosage forms were analyzed and met all of the qualitative and quantitative requirements. The methods met the requirements of method validation for accuracy with a percentage of recovery of 100.22 %, precision with relative standard deviation of 0.48 %, linearity with a correlation coefficient of 0.9992, limit of detection of 11.17 mg per mL, limit of quantitation of 33.84 mg per mL, and good specificity results. In this study, the Fourier Transform Infrared spectrophotometry method was successfully developed and validated for application in identification and determination of metformin hydrochloride in marketed tablet dosage form.

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 &lt;0.46 and &lt;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.

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