scholarly journals Spectrophotometric Detection of Glyphosate in Water by Complex Formation between Bis 5-Phenyldipyrrinate of Nickel (II) and Glyphosate

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 719 ◽  
Author(s):  
Aline Romero-Natale ◽  
Ilaria Palchetti ◽  
Mayra Avelar ◽  
Enrique González-Vergara ◽  
José Garate-Morales ◽  
...  
Keyword(s):  
Complex Formation ◽  
High Selectivity ◽  
High Sensitivity ◽  
Urban Groundwater ◽  
Molecular Geometry ◽  
Theoretical Studies ◽  
Spectrophotometric Detection ◽  
Short Response Time ◽  
Distorted Octahedral

A spectrophotometric method for the determination of glyphosate based on the monitoring of a complex formation between bis 5-phenyldipyrrinate of nickel (II) and the herbicide was developed. The method showed a short response time (10 s), high selectivity (very low interference from other pesticides and salts), and high sensitivity (LOD 2.07 × 10−7 mol/L, LOQ 9.87 × 10−7 mol/L, and a Kd from 1.75 × 10−6 to 6.95 × 10−6 mol/L). The Job plot showed that complex formation occurs with a 1:1 stoichiometry. The method was successfully applied in potable, urban, groundwater, and residual-treated water samples, showing high precision (0.34–2.9%) and accuracy (87.20–119.04%). The structure of the complex was elucidated through theoretical studies demonstrating that the nickel in the bis 5-phenyldipyrrinate forms a distorted octahedral molecular geometry by expanding its coordination number through one bond with the nitrogen and another with the oxygen of the glyphosate’ carboxyl group, at distances between 1.89–2.08 Å.

Sensitive and rapid biosensor for the determination of rhamnose based on the catalytic effect of the oxidation of calcein by H2O2

2014 ◽  
Vol 6 (21) ◽  
pp. 8779-8784
Author(s):  
Jia-Ming Liu ◽  
Zhen-bo Liu ◽  
Qitong Huang ◽  
Xiaofeng Lin
Keyword(s):  
Catalytic Reaction ◽  
High Selectivity ◽  
Catalytic Effect ◽  
High Sensitivity ◽  
Fluorescence Method

We report a new catalytic biosensor for the detection of rhamnose (Rha) based on combining the high sensitivity of a fluorescence method with the high selectivity of a catalytic reaction.

Determination of trace uranium by a photo-catalytic resonance fluorescence method coupled with dual cloud point extraction

2016 ◽  
Vol 8 (30) ◽  
pp. 5984-5993 ◽  
Author(s):  
Guirong Li ◽  
Jiekang Li ◽  
Qian Han
Keyword(s):  
Cloud Point ◽  
High Selectivity ◽  
Cloud Point Extraction ◽  
Low Cost ◽  
High Sensitivity ◽  
Fluorescence Method ◽  
Resonance Fluorescence ◽  
Complex Samples ◽  
Resonance Fluorescence Method

(1) Extracting and purifying uranium in complex samples by dCPE with [UO22+–SA1]. (2) Detecting uranium super sensitively by a photocatalytic RF method with [UO22+–SA2]. (3) Coupling with separation, purification and analysis procedures exhibited a number of advantages, including high selectivity, high sensitivity and low cost.

A micromethod for quantitative determination of iodoamino acids in thyroglobulin

1997 ◽  
Vol 153 (1) ◽  
pp. 99-104 ◽  
Author(s):  
N Baudry ◽  
B Mallet ◽  
P J Lejeune ◽  
L Vinet ◽  
J L Franc
Keyword(s):  
Acetic Acid ◽  
Enzymatic Hydrolysis ◽  
Mobile Phase ◽  
High Sensitivity ◽  
The Other ◽  
Reverse Phase Hplc ◽  
Reverse Phase ◽  
Spectrophotometric Detection ◽  
Hydrolysis Of

Abstract We describe a new method for quantification of iodoamino acids after enzymatic hydrolysis of thyroglobulin. The procedure involves separation of monoiodotyrosine (MIT), diiodotyrosine, tri-iodothyronine and thyroxine by reverse phase HPLC with a Vydac C18 stationary phase and a mobile phase of water–acetonitrile–acetic acid. The separation is monitored by sensitive spectrophotometric detection through a 96-well microplate system based on the catalytic Sandell–Kolthoff reaction of iodide on the oxidation of arsenic(III) by cerium(IV). This new microassay is particularly convenient because of its high sensitivity and its rapidity (less than 2 h). It can detect 1 pmol MIT and 0·5 pmol of the other three iodoamino acids with a recovery higher than 96%. Moreover, the 96-well microplate system allows many samples to be tested simultaneously and avoids the use of radiolabeled iodine. Journal of Endocrinology (1997) 153, 99–104

scholarly journals Selective Thallium (I) Ion Sensor Based on Functionalised ZnO Nanorods

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Z. H. Ibupoto ◽  
Syed M. Usman Ali ◽  
K. Khun ◽  
Magnus Willander
Keyword(s):  
High Selectivity ◽  
Zno Nanorods ◽  
High Sensitivity ◽  
Fast Response ◽  
Indicator Electrode ◽  
Coated Glass Substrate ◽  
Ion Sensor ◽  
Potentiometric Response ◽  
Growth Method

Well controlled in length and highly aligned ZnO nanorods were grown on the gold-coated glass substrate by hydrothermal growth method. ZnO nanorods were functionalised with selective thallium (I) ion ionophore dibenzyldiaza-18-crown-6 (DBzDA18C6). The thallium ion sensor showed wide linear potentiometric response to thallium (I) ion concentrations ( M to  M) with high sensitivity of 36.87 ± 1.49 mV/decade. Moreover, thallium (I) ion demonstrated fast response time of less than 5 s, high selectivity, reproducibility, storage stability, and negligible response to common interferents. The proposed thallium (I) ion-sensor electrode was also used as an indicator electrode in the potentiometric titration, and it has shown good stoichiometric response for the determination of thallium (I) ion.

scholarly journals New UHPLC-QqQ-MS/MS Method for the Rapid and Sensitive Analysis of Ascorbic and Dehydroascorbic Acids in Plant Foods

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1632 ◽  
Author(s):  
Nieves Baenas ◽  
Francisco J. Salar ◽  
Raúl Domínguez-Perles ◽  
Cristina García-Viguera
Keyword(s):  
Matrix Effect ◽  
High Performance ◽  
High Selectivity ◽  
Dehydroascorbic Acid ◽  
High Sensitivity ◽  
Practical Application ◽  
Quadrupole Mass ◽  
Internal Standards ◽  
The Matrix

A new method using ultra high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS) methodology was developed for the determination of ascorbic acid (AA) and dehydroascorbic acid (DHAA) contents in liquid and solid vegetable samples. The advantages of this method are speed, high sensitivity and practical application. In accordance with these advantages, the present method allows the simultaneous determination of AA and DHAA without previous reduction/derivatization of DHAA and without the use of internal standards in the samples. This is of high interest in routine analysis, providing a simpler sample preparation, as well as enhanced accuracy and robustness. Its validation included selectivity, sensitivity and linearity, precision and accuracy, matrix effect, and recovery. The results showed high selectivity and sensitivity, with calibration curves ranging from 10 to 500 ng mL−1 and from 50 to 500 ng mL−1 for AA and DHAA, respectively. Appropriate dilutions for each sample are necessary to avoid the matrix effect with accepted recoveries.

A rhodamine B-based lysosomal pH probe

2015 ◽  
Vol 3 (5) ◽  
pp. 919-925 ◽  
Author(s):  
Shi-Li Shen ◽  
Xin-Peng Chen ◽  
Xiao-Fan Zhang ◽  
Jun-Ying Miao ◽  
Bao-Xiang Zhao
Keyword(s):  
Response Time ◽  
Rhodamine B ◽  
High Selectivity ◽  
High Sensitivity ◽  
Living Cells ◽  
Acidic Ph ◽  
Ph Change ◽  
Short Response Time ◽  
Lysosomal Ph ◽  
Ph Probe

A novel rhodamine B-based lysosomal pH probe RML was developed. RML responded to acidic pH with short response time, high selectivity and high sensitivity and could detect lysosomal pH change in living cells.

Colorimetric Determination of Fluoride in Drinking Groundwater using a Polymeric Zirconium Complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline

2013 ◽  
Vol 12 (7) ◽  
pp. 460-465
Author(s):  
Sameer Amereih ◽  
Zaher Barghouthi ◽  
Lamees Majjiad
Keyword(s):  
Drinking Water ◽  
Detection Limit ◽  
Complex Formation ◽  
Molar Absorptivity ◽  
Colorimetric Determination ◽  
Zirconium Complex ◽  
Reliable Determination ◽  
Percentage Recovery ◽  
Quantitation Limit

A sensitive colorimetric determination of fluoride in drinking water has been developed using a polymeric zirconium complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline as fluoride reagents. The method allowed a reliable determination of fluoride in range of (0.0-1.5) mg L-1. The molar absorptivity of the complex formation is 7695 ± 27 L mol-1 cm-1 at 460 nm. The sensitivity, detection limit, quantitation limit, and percentage recovery for 1.0 mg L-1 fluoride for the proposed method were found to be 0.353 ± 0.013 μg mL-1, 0.1 mg L-1, 0.3 mg L-1, and 101.7 ± 4.1, respectively.

The Stabilizing Effect of Pre-Equilibria: A Trifluoromethyl Complex as CF2 Reservoir in Catalytic Olefin Difluorocarbenation

2020 ◽  
Author(s):  
Thomas Louis-Goff ◽  
Huu Vinh Trinh ◽  
Eileen Chen ◽  
Arnold L. Rheingold ◽  
Christian Ehm ◽  
...  
Keyword(s):  
High Selectivity ◽  
Side Reactions ◽  
Theoretical Studies ◽  
Attractive Feature ◽  
Catalyst Recovery ◽  
Wide Range ◽  
Stabilizing Effect ◽  
Experimental And Theoretical Studies

A new, efficient, catalytic difluorocarbenation of olefins to give 1,1-difluorocyclopropanes is presented. The catalyst, an organobismuth complex, uses TMSCF<sub>3</sub> as a stoichiometric difluorocarbene source. We demonstrate both the viability and robustness of this reaction over a wide range of alkenes and alkynes, including electron-poor alkenes, to generate the corresponding 1,1-difluorocyclopropanes and 1,1-difluorocyclopropenes. Ease of catalyst recovery from the reaction mixture is another attractive feature of this method. In depth experimental and theoretical studies showed that the key difluorocarbene-generating step proceeds through a bismuth non-redox synchronous mechanism generating a highly reactive free CF<sub>2</sub> in an endergonic pre-equilibrium. It is the reversibility when generating the difluorocarbene that accounts for the high selectivity, while minimizing CF<sub>2</sub>-recombination side-reactions.

Atomic absorption determination of Hg (II), Cd (II), and As (III) in natural and waste water after preliminary group preconcentration

2019 ◽  
Vol 85 (2) ◽  
pp. 12-16
Author(s):  
I. V. Saunina ◽  
E. N. Gribanov ◽  
E. R. Oskotskaya
Keyword(s):  
Waste Water ◽  
Atomic Absorption ◽  
High Sensitivity ◽  
Distribution Coefficients ◽  
Neutral Medium ◽  
Atomic Absorption Determination ◽  
Absorption Determination ◽  
Relative Standard ◽  
Preliminary Group

The sorption of Hg (II), Cd (II), and As (III) by natural aluminosilicate is studied. It is shown that the mineral absorbs those toxicants in a rather wide pH range, quantitative extraction of analytes being achieved in a neutral or close to neutral medium (pH values range within 7.0 - 8.0; 6.3 - 7.5; 7.4 - 8.5 for Hg (II), As (III), and Cd (II), respectively). The effect of the time of phase contact on the degree of extraction of elements is shown. The sorption capacity of the mineral in optimal conditions of the medium acidity (0.06 mmol/g for mercury, 0.31 mmol/g for cadmium, and 0.52 mmol/g for arsenic) is determined. The distribution coefficients attain values of aboutnX 103-nX 104. A new combined method for determination of Hg (II), Cd (II), and As (III) in natural and waste water is developed and tested. The method consists in a preliminary group sorption concentration of the analytes by aluminosilicate, desorption of the analytes from the surface of the mineral and their subsequent atomic absorption determination. The correctness of the method is verified in analysis of spiked samples. The method is easy to use and exhibits high sensitivity, reproducibility and accuracy of analyte determination. The relative standard deviation does not exceed 0.13. Economic availability and possibility of using domestic sorption materials are the important advantages of the proposed procedure which can be used in the practice of laboratories monitoring the quality and safety of environmental objects.

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