scholarly journals Modified Screen-Printed Electrode for Determination of Imidacloprid in Water Samples: A Preliminary Study

2019 ◽  
Vol 1 (2) ◽  
pp. 41-50
Author(s):  
Azrilawani Ahmad ◽  
Nur Anis Zafirah Zainordin ◽  
Nur Amira Jaafar
Keyword(s):  
Water Samples ◽  
Limit Of Detection ◽  
Supporting Electrolyte ◽  
Reduction Peak ◽  
Self Assembled Monolayer ◽  
Limit Of Quantification ◽  
Peak Current ◽  
Preliminary Study ◽  
Screen Printed

A preliminary assessment of a simple and rapid electrochemical method was carried out to analyse imidacloprid (IMI) in water samples using cyclic voltammetry (CV) based on modified screen-printed gold electrode (SPGE). Self-assembled monolayer (SAM) was optimized using 11-mercaptoundecanoic acid (11-MUA) with several parameters such as scan rates, type of supporting electrolyte, and pH of the supporting electrolyte. The modified SPGE showed high suppressed current against the potential due to the formation of a monolayer on the electrode surface. Surface morphology of the electrode was analysed using Scanning Electron Microscopy (SEM) confirming that 11-MUA was present on the modified SPGE. The water samples were collected from GM Peladang, Kuala Terengganu and two locations at Universiti Malaysia Terengganu. Method detection limit was expressed as limit of detection (LOD) and limit of quantification (LOQ) for modified SPGE which were calculated at 3.784 and 12.613 mg/L in water samples, respectively. This study showed that the reduction peak current observed on the modified electrode was lower compared with oxidation peak current. Hence, gold is unsuitable for IMI detection.

Determination of hydrazine at Ontario nuclear power plants

2015 ◽  
Vol 7 (23) ◽  
pp. 9825-9834 ◽  
Author(s):  
Slobodan V. Jovanovic ◽  
Thomas Zakharov ◽  
Hemendra Mulye ◽  
Duck Kim ◽  
Kelly-Anne Fagan
Keyword(s):  
Ion Chromatography ◽  
Water Samples ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Limit Of Detection ◽  
Limit Of Quantification ◽  
Amperometric Detector ◽  
Sensitive Method

In this study, we developed and validated a sensitive method for the determination of hydrazine in water samples using ion chromatography coupled with an amperometric detector (limit of detection (LOD) = 0.02 μg L−1 and limit of quantification (LOQ) = 0.1 μg L−1).

Determination of Se(iv) by adsorptive cathodic stripping voltammetry at a Bi/Hg film electrode

2015 ◽  
Vol 7 (5) ◽  
pp. 2121-2128 ◽  
Author(s):  
Parisa Sharifian ◽  
Alireza Aliakbar
Keyword(s):  
Water Samples ◽  
Limit Of Detection ◽  
Stripping Voltammetry ◽  
Open Circuit ◽  
Film Electrode ◽  
Limit Of Quantification ◽  
Cathodic Stripping Voltammetry ◽  
Analytical Range ◽  
Cathodic Stripping

Method and conditions: determination of trace amounts of Se(IV) by adsorptive cathodic stripping voltammetry at the Bi/Hg film electrode in an open circuit system; limit of detection: 0.07 ng mL−1; limit of quantification: 0.25 ng mL−1; RSD: 2.4% (for five replications of 5 ng mL−1 of Se(iv)); analytical range: 2–50 ng mL−1; interference: selective for Se(iv) – no interference; application: determination of Se(iv) in vegetable, fruits and water samples.

scholarly journals Extraction and Determination of Oxymatrine Pesticide in Environmental Sample and in its Formulation using High-Performance Liquid Chromatography

2020 ◽  
Vol 8 (2) ◽  
pp. 1-7
Author(s):  
Ihsan M. Shaheed ◽  
Saadiyah A. Dhahir
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Water Samples ◽  
High Performance ◽  
Limit Of Detection ◽  
Limit Of Quantification ◽  
Chromatography Method ◽  
Relative Standard ◽  
Dispersive Liquid Liquid Microextraction

The quinolizindine alkaloid compound, oxymatrine pesticide, was analysis in the river water samples collected from different agriculture areas in the Iraqi city of Kerbala and also in its formulation using developed reverse-phase high-performance liquid chromatography method. Acetonitrile:methanol (60:40 v/v) was chosen as mobile phase at pH (7.0), flow rate 0.5 mL/min, and 20 µL as volume injection. Modified ecological-friendly method, dispersive liquid-liquid microextraction, was used for the extraction of oxymatrine from water samples. Linearity study was constructed from 0.1 to 70 μg/mL at λmax 205 nm. The limit of detection and limit of quantification were 0.025 and 0.082 μg/mL, respectively, and the relative standard deviation (RSD) % was 0.518%. Three spiked levels of concentration (20.0, 40.0, and 70.0 μg/mL) were used for the validation method. The percentage recovery for the three spiked samples was ranged between 98.743 and 99.432 and the RSD% was between 0.051 and 0.202%, the formulation studies of oxymatrine between 99.487 and 99.798, and the RSD% was ranged from 0.045 to 0.057%. The developed method can be used accurately and selectively for the determination of oxymatrine in environmental samples and in the formulation.

scholarly journals EXTRACTION AND DETERMINATION OF TEBUCONAZOLE IN ENVIRONMENTAL SAMPLES FROM THE CITY OF KERBALA, IRAQ AND IN ITS FORMULATION USING HIGH- PERFORMANCE LIQUID CHROMATOGRAPHY (HPLC)

2020 ◽  
Vol 17 (34) ◽  
pp. 1046-1054
Author(s):  
Ihsan Mahdi SHAHEED ◽  
Saadiyah Ahmed DHAHIR
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Water Samples ◽  
High Performance ◽  
Limit Of Detection ◽  
Limit Of Quantification ◽  
Chromatography Method ◽  
Percentage Recovery ◽  
Relative Standard

The triazole, tebuconazole pesticide, was determined in its formulation and also in the river water samples collected from different agriculture areas in the Iraqui city of Kerbala using developed high-performance liquid chromatography method(HPLC) with UV-visible detection, The mobile composition phase was a mixture of acetonitrile:methanol (50:50 v/v) and the column was C18 (250 cm x 4.6 mm,5μm). Also modified dispersive liquidliquid microextraction (DLLME), which is regarded as an ecological -friendly method, was used for the extraction of tebuconazole from water samples using acetonitrile and chloroform as solvents extraction and dispersive agent, respectively. Linearity to maintain the calibration curve was achieved from (0.1-70) μg.mL-1 with a limit of detection(0.053) μg.mL-1 and limit of quantification (0.174) μg.mL-1. Three spiked levels of concentration (1.0, 5.0, and 10) μg.mL-1 were used for the validation of the method. The relative standard deviation (RSD%) was (0.294- 0.813)%, and the percentage recovery was (100.001-100.005). The formulation studies for two different concentrations (10 and 40) μg.mL-1, which prepared from tebuconazole formulation (Raxil ODS2 2%), gave acceptable percentage recovery between (98.956-99.833). The developed method can be used accurately for the determination of tebuconazole in water samples and in the formulation of tebuconazole effectively.

Voltammetric Determination of Diazepam on Antimony Film Screen-Printed Electrode in Pharmaceutical Formulations

2020 ◽  
Vol 16 ◽  
Author(s):  
Vesna Antunović ◽  
Rada Baošić ◽  
Aleksandar Lolić
Keyword(s):  
Modified Electrode ◽  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Ex Situ ◽  
Screen Printed Electrode ◽  
Limit Of Quantification ◽  
Azomethine Group ◽  
Antimony Film ◽  
Screen Printed

Background: Diazepam belongs to the group of 1,4-benzodiapines. It is used for the treatment of anxiety, convulsions and as a muscle relaxant. The presence of 4,5-azomethine group enables its electrochemical detection Introduction: A screen-printed electrode modified with antimony film was used for the determination of diazepam in pharmaceutical preparations Methods: Electrode modification was done by ex-situ deposition of antimony on commercially available screen-printed electrode. Parameters affecting the electroanalytical response of the sensor, such as deposition potential, deposition time, and antimony concentration, were examined and optimized. The modified electrode showed enhanced electroactivity for diazepam reduction compared to unmodified electrode. Under optimal conditions, linear sweep voltammetry was used for the determination of analyte Results: The sensor showed linear dependence in the range from 0.5 to 10 μmol/L, the correlation coefficient was 0.9992. The limit of detection was 0.33 μmol/L, corresponding limit of quantification was 1.08 μmol/L. Modification enabled determination of diazepam in the presence of oxygen. Conclusion: The modified electrode was used for the determination of diazepam in tablets. Results confirmed the applicability of the electrochemical sensor

scholarly journals A Method Validation for Simultaneous Determination of Phthalates and Bisphenol A Released from Plastic Water Containers

2019 ◽  
Vol 9 (14) ◽  
pp. 2945 ◽  
Author(s):  
Ivan Notardonato ◽  
Carmela Protano ◽  
Matteo Vitali ◽  
Badal Bhattacharya ◽  
Pasquale Avino
Keyword(s):  
Bisphenol A ◽  
Simultaneous Determination ◽  
Water Samples ◽  
Limit Of Detection ◽  
Tap Water ◽  
Phthalate Esters ◽  
Analytical Determination ◽  
Limit Of Quantification ◽  
Plastic Container

Phthalates (or phthalate esters, PAEs) and bisphenol A (BPA) are widely used in various industries, particularly in the fields of cosmetics and packaging, and they increase the malleability and workability of materials. As a result of their use, some international health organizations have begun to study them. In this study, the authors developed a methodology for the simultaneous determination of dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP); dibutyl phthalate (DBP), bis(2-ethylhexyl) phthalate (DEHP); di-n-octyl-phthalate (DnOP) and bisphenol A (BPA) from drinking and non-potable waters. The extraction of PAEs and BPA was performed using a solvent-based dispersive liquid–liquid microextraction (SB-DLLME) method. The analytical determination was performed using a gas chromatography–ion trap mass spectrometry (GC-IT/MS) analysis. The entire procedure was validated as recoveries were studied according to the volume and the extraction solvent used, pH, and ionic strength. Dynamic linearity ranges and linear equations of all the compounds were experimentally determined as well as the limit of detection (LOD) (1–8 ng mL−1) and the limit of quantification (LOQ) (5–14 ng mL−1), reproducibility, and sensitivity. The method was applied to 15 water samples (mineral water and tap water) for determining PAEs and BPA released from the plastic container. After the release simulation, four PAEs (i.e., DiBP, DBP, DHEP, and DnOP) were determined at very low concentrations (below 1.2 ng mL−1) in two water samples from (sport) bottles.

scholarly journals La2O3/Co3O4 nanocomposite modified screen printed electrode for voltammetric determination of sertraline

2020 ◽  
Vol 85 (4) ◽  
pp. 505-515
Author(s):  
Sayed Mohammadi ◽  
Hadi Beitollahi ◽  
Tahereh Rohani ◽  
Hossein Allahabadi ◽  
Somayeh Tajik
Keyword(s):  
Limit Of Detection ◽  
Electrochemical Determination ◽  
Current Response ◽  
Screen Printed Electrode ◽  
Peak Current ◽  
Anodic Peak Current ◽  
Pulse Voltammetry ◽  
Significant Increment ◽  
Screen Printed

La2O3/Co3O4 nanocomposite was synthesized and then used for the modification of screen-printed electrode (SPE) prior to the electrochemical determination of sertraline. A significant increment in peak current response was observed and peak potential also shifted towards less positive potentials showing the facilitated oxidation procedure at surface of modified SPE (La2O3/ /Co3O4/SPE). The quantitative determination of sertraline was carried out by using different pulse voltammetry and the anodic peak current was found to increase with increasing sertraline concentration in the linear range of 5.0400.0 ?M with limit of detection as 1.0 ?M. The prepared La2O3/Co3O4/SPE has been successfully used for detecting sertraline in sertraline tablet and urine samples with excellent recoveries.

scholarly journals Spectrophotometric Determination of Bismuth(III) with Arsenazo(III) Reagent in Water samples and Veterinary Preparation

2013 ◽  
Vol 10 (3) ◽  
pp. 986-996
Author(s):  
Baghdad Science Journal
Keyword(s):  
Water Samples ◽  
Limit Of Detection ◽  
Molar Absorptivity ◽  
Water Soluble ◽  
Arsenazo Iii ◽  
Solution Ph ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
Composite Mixture

A simple , sensitive and accurate spectrophotometric method for the trace determination of bismuth (III) has been developed .This method is based on the reaction of bismuth (III) with arsenazo(III) in acid solution (pH=1.9) to form a blue water soluble complex which exhibits maximum absorption at 612nm .Beer's law is obeyed over the concentration range of 2-85 ?g bismuth (III) in a final volume of 20 mL( i.e. 0.1 – 4.25?g.mL-1) with a correlation coefficient of (0.9981) and molar absorptivity 1.9×104 L.mol-1.cm-1 . The limit of detection (LOD) and the limit of quantification (LOQ) are 0.0633 and 0.0847 ?g.mL-1 , respectively . Under optimum conditions,the stoichiometry of the reaction between bismuth (III) and arsenazo(III) reagent was found to be 1:2. The recoveries were obtained in the range of 98.9 - 100.0% and a relative standard deviation of ±0.59 to ±2.73% depending on the concentration level of bismuth. The effect of interferences by a number of common cations and anions in the presence of composite mixture has been studied .The proposed method has been applied successfully for determination of bismuth in water samples and veterinary preparation .

scholarly journals Vortex Assisted Liquid-Liquid Microextraction with Back Extraction of Repaglinide, Glibenclamide and Glimepiride in Water Samples

2021 ◽  
Vol 50 (5) ◽  
pp. 1297-1307
Author(s):  
Sohaib Jumaah Owaid Luhaib ◽  
Noorfatimah Yahaya ◽  
Anas Alshishani ◽  
Maizatul Najwa Jajuli ◽  
Mazidatulakmam Miskam
Keyword(s):  
Water Samples ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Aqueous Sample ◽  
Back Extraction ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
Liquid Microextraction

A new analytical method based on vortex-assisted liquid-liquid microextraction with back extraction (VALLME-BE) coupled with high performance liquid chromatography was developed for the simultaneous determination of antidiabetic drugs; repaglinide, glibenclamide, and glimepiride in water samples. Chromatographic separation was achieved using C18 column (250 × 4.6 mm × 5 µm) and methanol-phosphate buffer (pH3.7) in the ratio of 70:30 v/v as a mobile phase at a flow rate of 1 mLmin-1. VALLME-BE was performed using 200 μL of n-octane dispersed into the aqueous sample (10 mL) with the aid of vortexing agitation. Then, the analytes were back-extracted from the organic solvent to 0.05 M NaOH (40 µL). Under these conditions, enrichment factor of 155-fold was achieved. The developed VALLME-BE method showed excellent linearity in the range of 30 to 1000 µgL-1 with limit of detection (LOD) of 0.41-1.66 µgL-1 and limit of quantification (LOQ) of 1.38-5.54. 41-1.66 µgL-1. VALLME-BE was applied for the determination of repaglinide, glibenclamide and glimepiride in water samples with the recoveries ranged from 83-109%. The relative standard deviation for inter-day and intra-day precision was less than 9.9%.

Spectrophotometeric Determination of Trifluoperazine HCL in Pure Forms and Pharmaceutical Preperations

2017 ◽  
Vol 9 (5) ◽  
Author(s):  
Mohammad Hamzah Hamzah ◽  
Rawa M M Taqi ◽  
Muna M. Hasan ◽  
Raid J. M. Al-Timimi
Keyword(s):  
Standard Method ◽  
Limit Of Detection ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Oxidizing Agent ◽  
Optimum Conditions ◽  
Limit Of Quantification ◽  
Cerium Ion ◽  
Blank Solution

A simple and accurate spectrophotometric method for the determination of Trifluoperazine HCl in pure and dosage forms was developed. The method is based on the reaction between Trifluoperazine HCl and p-chloroaniline in the presence of cerium ion as oxidizing agent which lead to the formation of violate color product that absorbed at a maximum wavelength 570nm while the blank solution was pink. Under the optimum conditions a linear relationship between the intensity and concentration of TRF in the range 4-50μg/ml was obtained . The molar absorptivity 3.74×103 L.mol-1.cm-1 , Limit of detection (2.21μg/ml), while limit of quantification was 7.39μg/ml. The proposed analytical method was compared with standard method using t-test and F-test , the obtained results shows there is no significant differences between proposed method and standard method. Based on that the proposed method can be used as an alternative method for the determination of TRF in pure and dosage forms.

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