scholarly journals Rapid Screening Method for Detecting Ethinyl Estradiol in Natural Water Employing Voltammetry

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Chalder Nogueira Nunes ◽  
Lucas Ely Pauluk ◽  
Maria Lurdes Felsner ◽  
Vanessa Egéa dos Anjos ◽  
Sueli Pércio Quináia
Keyword(s):  
Water Samples ◽  
Ethinyl Estradiol ◽  
Limit Of Detection ◽  
Screening Method ◽  
Mercury Electrode ◽  
Stripping Voltammetry ◽  
Electrochemical Process ◽  
Rapid Screening ◽  
Relative Standard ◽  
Pharmaceutically Active Compound

17α-Ethinyl estradiol (EE2), which is used worldwide in the treatment of some cancers and as a contraceptive, is often found in aquatic systems and is considered a pharmaceutically active compound (PhACs) in the environment. Current methods for the determination of this compound, such as chromatography, are expensive and lengthy and require large amounts of toxic organic solvents. In this work, a voltammetric procedure is developed and validated as a screening tool for detecting EE2 in water samples without prior extraction, clean-up, or derivatization steps. Application of the method we elaborate here to EE2 analysis is unprecedented. EE2 detection was carried out using differential pulse adsorptive cathodic stripping voltammetry (DP AdCSV) with a hanging mercury drop electrode (HMDE) in pH 7.0 Britton-Robinson buffer. The electrochemical process of EE2 reduction was investigated by cyclic voltammetry at different scan rates. Electroreduction of the hormone on a mercury electrode exhibited a peak at −1.16±0.02 V versus Ag/AgCl. The experimental parameters were as follows: −0.7 V accumulation potential, 150 s accumulation time, and 60 mV s−1scan rate. The limit of detection was 0.49 μg L−1for a preconcentration time of 150 s. Relative standard deviations were less than 13%. The method was applied to the detection of EE2 in water samples with recoveries ranging from 93.7 to 102.5%.

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.

Sensitive quantification of trace zinc in water samples by adsorptive stripping voltammetry

2013 ◽  
Vol 69 (2) ◽  
pp. 438-442 ◽  
Author(s):  
Shahryar Abbasi ◽  
Abbas Farmany ◽  
Mahmoud Roushani ◽  
Seyede Shima Mortazavi
Keyword(s):  
Water Samples ◽  
Mineral Water ◽  
Stripping Voltammetry ◽  
Adsorptive Stripping Voltammetry ◽  
Complexing Agent ◽  
Peak Current ◽  
Relative Standard ◽  
Preconcentration Time ◽  
Influence Of Ph

A simple and sensitive adsorptive stripping voltammetry method was developed for determination of Zn using N-nitrozo-N-phenylhydroxylamine (cupferron) as a selective complexing agent. This complex absorbed on the hanging mercury drop electrode and created a sensitive peak current. The peak current and concentration of zinc accorded with a linear relationship in the range of 0.85–320 ng mL−1. The influence of pH and the nature of supporting electrolytes, concentration of ligand, preconcentration time and applied potential were investigated. The relative standard deviation at a concentration level of 50 ng mL−1 was 1.8%. The method was applied to the determination of zinc in city, river and mineral water samples, with satisfactory results.

scholarly journals Development of a Cloud-Point Extraction Method for Cobalt Determination in Natural Water Samples

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Mohammad Reza Jamali ◽  
Mohammad Gholinezhad ◽  
Saiedeh Balarostaghi ◽  
Reyhaneh Rahnama ◽  
Seyed Hojjat Allah Rahimi
Keyword(s):  
Cloud Point ◽  
Water Samples ◽  
Cloud Point Extraction ◽  
Limit Of Detection ◽  
Cobalt Content ◽  
Cobalt Ions ◽  
Flame Atomic Absorption ◽  
Relative Standard ◽  
Separation And Preconcentration ◽  
Triton X

A new, simple, and versatile cloud-point extraction (CPE) methodology has been developed for the separation and preconcentration of cobalt. The cobalt ions in the initial aqueous solution were complexed with 4-Benzylpiperidinedithiocarbamate, and Triton X-114 was added as surfactant. Dilution of the surfactant-rich phase with acidified ethanol was performed after phase separation, and the cobalt content was measured by flame atomic absorption spectrometry. The main factors affecting CPE procedure, such as pH, concentration of ligand, amount of Triton X-114, equilibrium temperature, and incubation time were investigated and optimized. Under the optimal conditions, the limit of detection (LOD) for cobalt was 0.5 μg L-1, with sensitivity enhancement factor (EF) of 67. Calibration curve was linear in the range of 2–150 μg L-1, and relative standard deviation was 3.2% (c=100 μg L-1;n=10). The proposed method was applied to the determination of trace cobalt in real water samples with satisfactory analytical results.

scholarly journals Use of Dispersive Liquid-Liquid Microextraction and UV-Vis Spectrophotometry for the Determination of Cadmium in Water Samples

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
J. Pérez-Outeiral ◽  
E. Millán ◽  
R. Garcia-Arrona
Keyword(s):  
Water Samples ◽  
Limit Of Detection ◽  
Experimental Conditions ◽  
Cadmium Determination ◽  
A Value ◽  
Relative Standard ◽  
Potential Applicability ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

A simple and inexpensive method for cadmium determination in water using dispersive liquid-liquid microextraction and ultraviolet-visible spectrophotometry was developed. In order to obtain the best experimental conditions, experimental design was applied. Calibration was made in the range of 10–100 μg/L, obtaining good linearity (R2 = 0.9947). The obtained limit of detection based on calibration curve was 8.5 μg/L. Intra- and interday repeatability were checked at two levels, obtaining relative standard deviation values from 9.0 to 13.3%. The enrichment factor had a value of 73. Metal interferences were also checked and tolerable limits were evaluated. Finally, the method was applied to cadmium determination in real spiked water samples. Therefore, the method showed potential applicability for cadmium determination in highly contaminated liquid samples.

scholarly journals Design, Synthesis, and Characterization of Tracers and Development of a Fluorescence Polarization Immunoassay for Rapid Screening of 4,4′-Dinitrocarbanilide in Chicken Muscle

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1822
Author(s):  
Qidi Zhang ◽  
Ming Zou ◽  
Wanyu Wang ◽  
Jinyan Li ◽  
Xiao Liang
Keyword(s):  
Fluorescence Polarization ◽  
Limit Of Detection ◽  
Screening Method ◽  
Sample Pretreatment ◽  
Cross Reactivity ◽  
Rapid Screening ◽  
Fluorescence Polarization Immunoassay ◽  
Design Synthesis ◽  
Chicken Muscle ◽  
Edible Tissues

The compound, 4,4′-dinitrocarbanilide (DNC), is the marker residue of concern in edible tissues of broilers fed with diets containing anticoccidial nicarbazin (NIC). In this study, 25 fluorescein-labeled DNC derivatives (tracers) are synthesized and characterized to develop a rapid fluorescence polarization immunoassay (FPIA) for the detection of DNC in chickens using DNC monoclonal antibodies (mAbs). The effect of the tracer structure on the sensitivity of the FPIA is investigated. Our results show that after optimization, the half maximal inhibitory concentrations (IC50) and limit of detection (LOD) of the FPIA in the buffer are 28.3 and 5.7 ng mL−1, respectively. No significant cross-reactivity (CR < 0.89%) with 15 DNC analogues is observed. The developed FPIA is validated for DNC detection in spiked chicken homogenates, and recoveries ranged from 74.2 to 85.8%, with coefficients of variation <8.6%. Moreover, the total time needed for the detection procedure of the FPIA, including sample pretreatment, is <40 min, which has not been achieved in any other immunoassays for DNC from literature. Our results demonstrate that the FPIA developed here is a simple, sensitive, specific, and reproducible screening method for DNC residues in chickens.

Rapid Screening Method for Aflatoxin M1 in Milk

1981 ◽  
Vol 64 (5) ◽  
pp. 1064-1066
Author(s):  
Charles E Holaday
Keyword(s):  
Limit Of Detection ◽  
Screening Method ◽  
Rapid Screening ◽  
Aflatoxin M1 ◽  
Fluorescent Band ◽  
Neutral Alumina ◽  
Rapid Screening Method ◽  
The Cost

Abstract A rapid screening method for detecting aflatoxin M1 in milk has been developed, based on minicolumn chromatography and requiring 8-10 min for each test. The minicolumn is packed with dry Florisil (100-200 mesh) on the bottom, anhydrous Na2S04 as the next layer, topped with neutral alumina (70-200 mesh) to which 8% water (wet basis) has been added. A blue fluorescent band at the Florisil-Na2SO4 interface indicates the presence of aflatoxin M1. The limit of detection is estimated to be about 0.2 μg/kg. Because several items are disposable, both the time to maintain glassware and the cost per determination are reduced.

scholarly journals Development of a Direct Competitive ELISA Kit for Detecting Deoxynivalenol Contamination in Wheat

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 50
Author(s):  
Li Han ◽  
Yue-Tao Li ◽  
Jin-Qing Jiang ◽  
Ren-Feng Li ◽  
Guo-Ying Fan ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
High Performance ◽  
Limit Of Detection ◽  
High Specificity ◽  
Hplc Method ◽  
Rapid Screening ◽  
Enzyme Linked Immunosorbent Assay ◽  
Detection Range ◽  
Technical Requirements ◽  
Relative Standard

This study was conducted to develop a self-assembled direct competitive enzyme-linked immunosorbent assay (dcELISA) kit for the detection of deoxynivalenol (DON) in food and feed grains. Based on the preparation of anti-DON monoclonal antibodies, we established a standard curve with dcELISA and optimized the detection conditions. The performance of the kit was evaluated by comparison with high-performance liquid chromatography (HPLC). The minimum detection limit of DON with the kit was 0.62 ng/mL, the linear range was from 1.0 to 113.24 ng/mL and the half-maximal inhibition concentration (IC50) was 6.61 ng/mL in the working buffer; there was a limit of detection (LOD) of 62 ng/g, and the detection range was from 100 to 11324 ng/g in authentic agricultural samples. We examined four samples of wheat bran, wheat flour, corn flour and corn for DON recovery. The average recovery was in the range of 77.1% to 107.0%, and the relative standard deviation (RSD) ranged from 4.2% to 11.9%. In addition, the kit has the advantages of high specificity, good stability, a long effective life and negligible sample matrix interference. Finally, wheat samples from farms in the six provinces of Henan, Anhui, Hebei, Shandong, Jiangsu and Gansu in China were analyzed by the kit. A total of 30 samples were randomly checked (five samples in each province), and the results were in good agreement with the standardized HPLC method. These tests showed that the dcELISA kit had good performance and met relevant technical requirements, and it had the characteristics of accuracy, reliability, convenience and high-throughput screening for DON detection. Therefore, the developed kit is suitable for rapid screening of DON in marketed products.

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.

Sample Preincubation Strategy for Sensitive and Quantitative Detection of Clenbuterol in Swine Urine Using a Fluorescent Microsphere–Based Immunochromatographic Assay

2014 ◽  
Vol 77 (11) ◽  
pp. 1998-2003 ◽  
Author(s):  
SHENG L. DENG ◽  
SHAN SHAN ◽  
CHAO L. XU ◽  
DAO F. LIU ◽  
YONG H. XIONG ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Rapid Screening ◽  
Immunochromatographic Assay ◽  
Quantitative Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fluorescent Microsphere ◽  
Swine Urine ◽  
Relative Standard

We describe an ultrasensitive and quantitative immunochromatographic assay to determine the amount of clenbuterol (CLB) in swine urine. In this study, fluorescein isothiocyanate polystyrene fluorescent microspheres were used as probes. A sample preincubation strategy was introduced to this immunochromatographic assay. Results showed that the strategy evidently improved the sensitivity and accuracy of lateral flow assay. The method was completed in 20 min, and a half-maximal inhibitory concentration of 0.13 μg liter−1 was obtained. The limit of detection of the proposed method to determine CLB in swine urine was 0.01 μg liter−1, which was lower than the limit of detection of immunochromatographic assays without preincubation. Intra-and interday recoveries of spiked swine urine ranged from 85.0 to 107.5%. The relative standard deviation values of the preincubated test strip ranged from 2.7 to 12.5%. Analysis of the CLB in swine urine samples showed that the result obtained from the lateral flow assay is consistent with that obtained from a commercial enzyme-linked immunosorbent assay kit. Our results suggest that the developed fluorescent microsphere–based immunochromatographic assay may be useful as a rapid screening method to detect CLB quantitatively.

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.

Sign in / Sign up

Export Citation Format

Share Document