scholarly journals A 4-(1H-Benzo[d]oxazole-2-yl)-2-methoxyphenol as Dual Selective Sensor for Cyanide Ion Detection

2019 ◽  
Vol 31 (3) ◽  
pp. 555-558 ◽  
Author(s):  
R. Rahmawati ◽  
B. Purwono ◽  
S. Hadisaputera
Keyword(s):  
Association Constant ◽  
Limit Of Detection ◽  
Ion Detection ◽  
Cyanide Ion ◽  
Fluorescence Titration ◽  
Dual Sensor ◽  
Uv Visible ◽  
Spectroscopic Titration ◽  
Dark Green ◽  
Selective Sensor

A dual sensor based on benzoxazole containing moiety S3 was successfully synthesized and applied for detection of CN− ion. The S3 molecule changed its colour for dark brown to dark green on addition of the CN− ion only in DMSO solvent. The limit of detection (LOD) and association constant (Kass) values was 0.4 × 10−6 M and 1.0 × 107 M−1; and 0.46 × 10−4 M and 1.0 × 105 M−1 determined by UV-visible spectroscopic titration and fluorescence titration, respectively.

scholarly journals Cyanine-based Fluorescent Probe for Cyanide Ion Detection

2021 ◽  
Author(s):  
Mahesh Gosi ◽  
Nagaraju Marepu ◽  
Yeturu Sunandamma
Keyword(s):  
Fluorescent Probe ◽  
Ion Detection ◽  
Cyanide Ion

scholarly journals A Novel Thiosemicarbazide-Based Fluorescent Chemosensor for Hypochlorite in Near-Perfect Aqueous Solution and Zebrafish

Chemosensors ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 65
Author(s):  
Minji Lee ◽  
Donghwan Choe ◽  
Soyoung Park ◽  
Hyeongjin Kim ◽  
Soomin Jeong ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Reactive Oxygen Species ◽  
Aqueous Solution ◽  
Fluorescence Quenching ◽  
Limit Of Detection ◽  
Fluorescent Sensor ◽  
Ionization Mass ◽  
Oxygen Species ◽  
Marked Selectivity ◽  
Uv Visible

A novel thiosemicarbazide-based fluorescent sensor (AFC) was developed. It was successfully applied to detect hypochlorite (ClO−) with fluorescence quenching in bis-tris buffer. The limit of detection of AFC for ClO− was analyzed to be 58.7 μM. Importantly, AFC could be employed as an efficient and practical fluorescent sensor for ClO− in water sample and zebrafish. Moreover, AFC showed a marked selectivity to ClO− over varied competitive analytes with reactive oxygen species. The detection process of AFC to ClO− was illustrated by UV–visible and fluorescent spectroscopy and electrospray ionization–mass spectrometry (ESI–MS).

scholarly journals DEVELOPMENT AND VALIDATION OF UV-SPECTROPHOTOMETRIC METHOD FOR ESTIMATION OF HYDROQUINONE IN BULK, MARKETED CREAM AND PREAPARED NLC FORMULATION

2017 ◽  
Vol 9 (5) ◽  
pp. 102
Author(s):  
Sukhjinder Kaur ◽  
Taranjit Kaur ◽  
Gurdeep Kaur ◽  
Shivani Verma
Keyword(s):  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Pure Form ◽  
Nanostructured Lipid Carrier ◽  
Limit Of Quantification ◽  
Double Beam ◽  
Uv Visible ◽  
Development And Validation

Objective: The aim of the present work was to develop a simple, rapid, accurate and economical UV-visible spectrophotometric method for the determination of hydroquinone (HQ) in its pure form, marketed formulation as well as in the prepared nanostructured lipid carrier (NLC) systems and to validate the developed method.Methods: HQ was estimated at UV maxima of 289.6 nm in pH 5.5 phosphate buffer using UV-Visible double beam spectrophotometer. Following the guidelines of the International Conference on Harmonization (ICH), the method was validated for various analytical parameters like linearity, precision, and accuracy robustness, ruggedness, limit of detection, quantification limit, and formulation analysis.Results: The obtained results of the analysis were validated statistically. Recovery studies were performed to confirm the accuracy of the proposed method. In the developed method, linearity over the concentration range of 5-40 μg/ml of HQ was observed with the correlation coefficient of 0.998 and found in good agreement with Beer Lambert’s law. The precision (intra-day and inter-day) of the method was found within official RCD limits (RSD<2%).Conclusion: The sensitivity of the method was assessed by determining the limit of detection and limit of quantification. It could be concluded from the results obtained that the purposed method for estimation of HQ in pure form, in the marketed ointment and in the prepared NLC-formulation was simple, rapid, accurate, precise and economical. It can be used successfully in the quality control of pharmaceutical formulations and for the routine laboratory analysis.

scholarly journals Highly Sensitive and Selective Colorimetric Sensor of Mercury (II) Based on Layer–by–Layer Deposition of Gold/Silver Bimetallic Nanoparticles

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4443
Author(s):  
Arjnarong Mathaweesansurn ◽  
Naratip Vittayakorn ◽  
Ekarat Detsri
Keyword(s):  
Bimetallic Nanoparticles ◽  
Limit Of Detection ◽  
Chemical Reduction ◽  
Colorimetric Sensor ◽  
Layer By Layer ◽  
Linear Relationships ◽  
Layer Deposition ◽  
Gold Silver ◽  
Ft Ir ◽  
Uv Visible

A new colorimetric sensor based on gold/silver bimetallic nanoparticles (Au–Ag BNPs) for the sensitive and selective detection of mercury (II) was developed. Gold nanoparticles (AuNPs) were synthesized by Turkevich method. The surface modification of AuNPs was modified by the layer–by–layer technique using poly(diallyl dimethylammonium chloride) which provided positively charged of AuNPs. Negatively charged silver nanoparticles (AgNPs) were synthesized by chemical reduction using poly(4–styrenesulfonic acid–co–maleic acid) as the stabilizing agent. The layer–by–layer assembly deposition technique was used to prepare Au–Ag BNPs of positively and negatively charged of AuNPs and AgNPs, respectively. The synthesized Au–Ag BNPs were characterized by a UV-visible spectrophotometer, zeta potential analyzer, FT–IR, TEM, XRD, and EDX. The Au–Ag BNPs sensor was able to detect mercury (II) in aqueous solution, visibly changing from brownish–orange to purple. The linear relationships of the UV-visible spectrometry demonstrate that the Au–Ag BNPs-based colorimetric sensor can be used for the quantitative analysis of mercury (II) in the range of 0.5–80 mg L−1, with the correlation coefficient, r2 = 0.9818. The limit of detection (LOD) of mercury (II) was found to be 0.526 + 0.001 mg L−1. The BNPs is also verified to have a good practical applicability for mercury (II) detection in the real samples.

scholarly journals Experimental Sensing and DFT Mechanism of Zn(II) Complex for Highly Sensitive and Selective Detection of Acetone

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 324
Author(s):  
Mohd. Muddassir ◽  
Mohammad Usman ◽  
Abdullah Alarifi ◽  
Mohd. Afzal ◽  
Khulud Abdullah Alshali ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Energy Barrier ◽  
Association Constant ◽  
Theoretical Calculations ◽  
Selective Detection ◽  
Acetone Molecule ◽  
Hydrogen Bonding Interactions ◽  
Highly Sensitive ◽  
Perchlorate Complex ◽  
Selective Sensor

In the present work, a new Zn(II) perchlorate complex with 2,2’–bipyridyl of formulation {[Zn(bipy)2(H2O)](ClO4)2} (1) was obtained and well analyzed. This chemosensor was evaluated as a selective sensor for acetone among the several different organic solvents(CH3OH, EtOH, i–PrOH, i–BuOH, CHCl3, CH2Cl2, CCl4, C6H6, C7H8, C8H10, C2H3N, C3H7NO, C4H8O2, C3H6O3) in a fluorescence turn–off response in accordance with theoretical calculations. Sensing experiments were performed at ambient temperature which shows the acetone molecule distinctly reduces transfer of energy barrier to complex 1 and hence, produces remarkable luminescent quenching. Also, the weak intermolecular hydrogen–bonding interactions thanks to the presence of various hydrogen bonding donors and acceptors, exist between ligand molecules, which were broken during fluorescence, resulting in quenching. The stoichiometry ratio and association constant were evaluated using Benesi–Hildebrand relation giving 1:1 stoichiometry between complex 1 and acetone. Additionally, DFT results can also explicate the significant response on complex 1 upon addition of acetone. This work is vital in a new loom for the detection of acetone and other ketones.

Development of a HeCd Laser-Based Fluorescence Detector for Analysis of Derivatized Biogenic Amines

1992 ◽  
Vol 46 (10) ◽  
pp. 1532-1539 ◽  
Author(s):  
J. M. Bostick ◽  
J. W. Strojek ◽  
T. Metcalf ◽  
T. Kuwana
Keyword(s):  
Biogenic Amines ◽  
Limit Of Detection ◽  
Laser Dye ◽  
Cyanide Ion ◽  
Fluorescence Detector ◽  
Optical Components ◽  
Output Wavelength ◽  
Highly Sensitive ◽  
Amine Adducts ◽  
Hecd Laser

The development of a highly sensitive laser-induced fluorescence (LIF) detector for HPLC is described. It was specifically designed to monitor the fluorescence emitted from biogenic amines which were derivatized by naphthalenedicarboxaldehyde (NDA) in the presence of cyanide ion. The product of the amine derivatization, cyanobenz[f]isoindole (CBI), absorbs radiation at the output wavelength of the HeCd laser (441.6 nm). Optimization of detector sensitivity included evaluation of both optical components and cell configurations. A laser dye, coumarin 7, served as the test analyte because its native spectral properties coincided with those of the CBI-amine adducts and because no derivatization step was required for each injection. A limit of detection (LOD) on the order of 2 × 10−12 M was reproducibly observed.

scholarly journals A simple azoquinoline based highly selective colorimetric sensor for CN− anion in aqueous media

2017 ◽  
Vol 95 (7) ◽  
pp. 771-777 ◽  
Author(s):  
Omer Kaan Koc ◽  
Hava Ozay
Keyword(s):  
Limit Of Detection ◽  
Aqueous Media ◽  
Interaction Mechanism ◽  
Solvent Mixture ◽  
H Nmr ◽  
Light Yellow ◽  
Host Guest Complex ◽  
Made In ◽  
Selective Sensor

Azoquinoline based sensor AZQ was designed and synthesized as a new molecular ion sensor containing an azo group in its structure. The structural characterization of AZQ was carried out using FTIR, NMR, mass, and elemental analysis. Then, the interaction of AZQ with anions was observed visually and UV–vis measurements were made in EtOH/H2O (1:1, v/v) solvent mixture. As a result of this investigation, it was determined that AZQ is a fast and highly selective sensor for CN− ions. The solution colour of AZQ changed from light yellow to orange only in the presence of CN− ions. The limit of detection of AZQ was calculated as 2.6 μmol/L from anion titration experiments. Also, to identify the interaction mechanism of AZQ with CN− ions, 1H NMR spectra of AZQ in the presence of CN− anions were recorded and the structure was proposed for AZQ-CN− host–guest complex.

Interaction of Antitumor Agent Mitoxantrone with Double Helical Synthetic Polyribonucleotides Poly(G)⋅Poly(C) and Poly(I)⋅Poly(C)

2017 ◽  
Vol 12 (04) ◽  
pp. 165-176
Author(s):  
Yuri S. Babayan ◽  
Sergey N. Hakobyan ◽  
Rusanna S. Ghazaryan ◽  
Mariam A. Shahinyan
Keyword(s):  
Complex Formation ◽  
Association Constant ◽  
Antitumor Agent ◽  
Visible Absorption ◽  
Double Stranded Rna ◽  
Base Specificity ◽  
Enthalpy And Entropy ◽  
Uv Visible ◽  
Bromide Interaction ◽  
System Entropy

The interaction of antitumor drug mitoxantrone (MTX) with double-stranded synthetic RNA homopolymers has been studied by means of spectroscopic (UV-Visible absorption, circular dichroism) techniques. The results show a base specificity in this interaction: the association constant with poly(G)[Formula: see text]poly(C) is higher than with poly(I)[Formula: see text]poly(C).Values of changes of the system enthalpy and entropy due to complex-formation were determined through the temperature dependence of the binding constant. Calculations show that due to the intercalation interaction of MTX, the values of changes of the system entropy and enthalpy differ from those obtained at ehtidium bromide interaction with synthetic polyribonucleotides, which shows that the intercalation interaction of MTX with double-stranded RNA significantly differs from that of ethidium bromide with RNA.

Analytical Method Development and Validation of UV-visible Spectrophotometric Method for the Estimation of Vildagliptin in Gastric Medium

Drug Research ◽  
2020 ◽  
Vol 70 (09) ◽  
pp. 417-423
Author(s):  
Beena Kumari ◽  
Aparna Khansili
Keyword(s):  
Melting Point ◽  
Spectrophotometric Method ◽  
Method Development ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Scanning Calorimetry ◽  
Limit Of Quantification ◽  
Double Beam ◽  
Uv Visible ◽  
Development And Validation

Abstract Background Vildagliptin is an antidiabetic agent, belongs to the dipeptidyl peptidase IV (DPP-4) inhibitors. Objective The aim of investigation was to develop a simple UV-visible Spectrophotometric method for the determination of vildagliptin in its pure form and pharmaceutical formulations, further to validate the developed method. Material and Methods Vildagliptin was estimated using UV-Visible double beam spectrophotometer at the wavelength of maximum absorption (210 nm) in acidic medium containing 0.1N HCl. The drug was characterized by melting point, Differential Scanning Calorimetry (DSC), and Fourier Transform Infra-Red (FTIR) techniques. The analysis of the drug was carried out by novel UV-Visible method which was validated analytical parameters like linearity, precision, and accuracy as per guidelines laid down by International Conference on Harmonization (ICH). Result Melting point of drug was found 154°C which is corresponds to its actual melting range. Similarly by the interpretation of spectra the drug was confirmed. The linear response for concentration range of 5–60 µg/ml of vildagliptin was recorded with regression coefficient 0.999. The accuracy was found between 98–101%. Precision for intraday and interday was found to be 1.263 and 1.162 respectively, which are within the limits. To establish the sensitivity of the method, limit of detection (LOD) and limit of quantification (LOQ) were determined which were found to be 0.951 µg/ml and 2.513 µg/ml respectively. Conclusion The UV method developed and validated for vildagliptin drug was found to be linear, accurate, precise and economical which can be used for the testing of its pharmaceutical formulations.

scholarly journals HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY ANALYTICAL METHOD VALIDATION FOR GLUTARALDEHYDE AND BENZALKONIUM CHLORIDE IN DISINFECTANTS

2018 ◽  
Vol 10 (1) ◽  
pp. 248
Author(s):  
Baitha Palanggatan Maggadani ◽  
Harmita . ◽  
Maizura Isfadhila
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Analytical Method ◽  
Benzalkonium Chloride ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Analytical Method Validation ◽  
Limit Of Quantitation ◽  
Uv Visible

Objective: The aim of this study was to produce a selective, accurate, and faster high-performance liquid chromatography (HPLC) analytical methodfor benzalkonium chloride and glutaraldehyde in disinfectants using ultraviolet (UV)-visible detection.Methods: Glutaraldehyde has no chromophore, so it was first derivatized using 2,4 dinitro phenylhydrazine. Acetonitrile:water (75:25) was used asthe mobile phase for glutaraldehyde and acetonitrile-acetate pH 4 (75:25) for benzalkonium chloride, both at a flow rate of 1.2 mL/min. The optimizedassay was validated with respect to accuracy, precision, linearity, selectivity, limit of quantitation (LOQ), and limit of detection (LOD).Results: The method was linear for benzalkonium chloride, with correlation coefficient of 0.9995, LOD of 14.55 ppm, and LOQ of 48.51 ppm. Thecorrelation coefficient for glutaraldehyde was 0.9995, with LOD of 0.49 ppm and LOQ of 1.64 ppm. Accuracy was between 98% and 102%, andprecision was below 2% for both the tests.Conclusion: The HPLC analytical method for benzalkonium chloride and glutaraldehyde in disinfectants using UV-visible detection in this researchwas successful to produce a selective, accurate, and faster method.

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