Determination of cyanide in blood by GC–MS using a new high selectivity derivatization reagent 1,2,3,3-tetramethyl-3H-indolium iodide

2022 ◽  
Author(s):  
Yasuhiro Morikawa ◽  
Keiji Nishiwaki ◽  
Shigeo Suzuki ◽  
Kazutaka Shiomi ◽  
Isao Nakanishi
Keyword(s):  
High Selectivity

Metal-organic framework derived metal oxide/reduced graphene oxide nanocomposite, a new tool for the determination of dipyridamole

2021 ◽  
Author(s):  
Naeime Salandari-Jolge ◽  
Ali A. Ensafi ◽  
Behzad Rezaei
Keyword(s):  
Myocardial Infarction ◽  
Graphene Oxide ◽  
High Performance ◽  
High Selectivity ◽  
Low Cost ◽  
Metal Organic Framework ◽  
Heart Patients ◽  
Reduced Graphene ◽  
Metal Organic

Dipyridamole is a prescribed medication used to treat cardiovascular diseases, angina pectoris, imaging tests for heart patients, and myocardial infarction. Therefore, high selectivity and sensitivity, low cost, and high-performance speed...

Selective Determination of Entecavir in the Presence of Its Oxidative Degradate by Spectrophotometric and Chromatographic Methods

2021 ◽  
Author(s):  
Heba M El-Sayed ◽  
Laila E Abdel Fattah ◽  
Hisham E Abdellatef ◽  
Maha A Hegazy ◽  
Mai M Abd El-Aziz
Keyword(s):  
High Selectivity ◽  
Oxidative Degradation ◽  
Hplc Method ◽  
Peak Amplitude ◽  
Quality Analysis ◽  
Official Method ◽  
Selective Determination ◽  
Significant Difference ◽  
Development And Validation

Abstract Background Entecavir (ENT) is an antiretroviral agent prescribed for treatment of HBV and HIV. Objective Development and validation of three simple, sensitive, selective, and precise methods for determination of ENT in presence of its oxidative degradation product (ENT deg.). Methods The first method was based on second derivative (D2) spectrophotometry through measuring the peak amplitude of D2 spectra at 293.6 nm. The second one is mean centering of the ratio spectra (MCR), which allowed measuring the peak amplitude at 280.0 nm. While the third method was HPLC; where ENT was separated from ENT deg. using Zobrax C18column and methanol: water (30:70, v/v), pH 3 as a mobile phase. The three developed methods were validated according to ICH guidelines. Results Linearity range of ENT was 5.00–50.00 μg/mL for both D2and MCR. However, higher sensitivity was achieved using HPLC (1.00–50.00 μg/mL). Accuracy of ENT were 100.60%±0.547, 101.55%±1.2071 and 100.61%±1.207 for D2, MCR and HPLC methods, respectively, and precision was within 1.280. Conclusions The developed methods were successfully applied for the determination of ENT in Tecavir® tablets without interference from ENT deg. They showed no significant difference compared with the official method as well as they could be applied in the quality analysis of ENT with high selectivity, accuracy, and precision. Highlights ENT was quantified using two spectrophotometric (D2 and MCR) methods and an HPLC method in presence of ENT deg. The proposed methods were applied to analysis of ENT tablets with high selectivity, sensitivity, and accuracy.

scholarly journals Gas Chromatographic Determination of Cyprodinil, Fludioxonil, Pyrimethanil, and Tebuconazole in Grapes, Must, and Wine

1997 ◽  
Vol 80 (4) ◽  
pp. 867-870 ◽  
Author(s):  
Paolo Cabras ◽  
Alberto Angioni ◽  
Vincenzo L Garau ◽  
Elizabeth V Minelli
Keyword(s):  
Chromatographic Method ◽  
High Selectivity ◽  
Chromatographic Determination ◽  
Mass Spectrometric ◽  
On Line ◽  
One Step ◽  
Low Sensitivity ◽  
Gas Chromatographic Method ◽  
Nitrogen Phosphorus

Abstract A rapid and simple gas chromatographic method for determinating cyprodinil, fludioxonil, pyrimethanil, and tebuconazole in grapes, must, and wine is described. An on-line microextraction method was used with a one-step extraction–partition procedure. Nitrogen–phosphorus and mass spectrometric detectors were used, because of their low sensitivity and high selectivity. Because of high selectivity of detector, no cleanup was necessary and the extract was concentrated 5 times. Recoveries from fortified grapes, must, and wine ranged from 93 to 110%. Limits of determination were 0.05 mg/kg for cyprodinil and pyrimethanil and 0.10 mg/kg for fludioxonil and tebuconazole.

scholarly journals Determination of Malathion, Coumaphos, and Fluvalinate Residues in Honey by Gas Chromatography with Nitrogen–Phosphorus or Electron Capture Detectors

2000 ◽  
Vol 83 (1) ◽  
pp. 178-182 ◽  
Author(s):  
Urania Menkissoglu-Spiroudi ◽  
Grigorios C Diamantidis ◽  
Vassiliki E Georgiou ◽  
Andreas T Thrasyvoulou
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
High Selectivity ◽  
Order Model ◽  
First Order ◽  
Quantitation Limit ◽  
Coefficients Of Variation ◽  
Electron Capture Detectors ◽  
Nitrogen Phosphorus

Abstract A rapid, reliable, and inexpensive extraction method was developed to determine acaricide residues in honey by gas chromatography (GC) with nitrogen–phosphorus (NP) or electron capture (EC) detectors. Because of the high selectivity of the NP detector, no interfering peaks were present and no cleanup was necessary. A simple cleanup step is proposed for the GC–ECD analysis. Recoveries from spiked honey samples ranged from 79 to 94.4%, with coefficients of variation of 0.3–18.5%. The quantitation limit obtained was 0.015 mg/kg for malathion, 0.020 mg/kg for coumaphos, and 0.005 mg/kg for fluvalinate. The method was used to determine the disappearance of malathion and coumaphos residues from honey samples collected from beehives treated with these acaricides. The disappearance of both acaricides was rapid and followed a first-order model for the duration of the experiment.

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.

Construction and Application of Molecularly Imprinted Film Sensor on Determination of Chlorpyrifos in Water

2014 ◽  
Vol 936 ◽  
pp. 843-849 ◽  
Author(s):  
Gui Feng Lin ◽  
Yan Hong Wang ◽  
Guo Chen Li ◽  
Wen Bai ◽  
Hong Zhang ◽  
...  
Keyword(s):  
High Selectivity ◽  
Constant Current ◽  
Film Sensor ◽  
Molecularly Imprinted ◽  
Binding Characteristics ◽  
Response Characteristics ◽  
Recognition Element ◽  
Sensitive Film ◽  
Molecularly Imprinted Film

Molecularly imprinted microspheres for recognition of chlorpyrifos were prepared by thermal initiation and precipitation polymerization, and were characterized using scanning electron microscope and infrared spectroscopy. Binding characteristics of the microspheres were also investigated. Sensitive film electrode of chlorpyrifos was prepared using the microspheres above on the surface of gold electrode by spin coating. Electrochemical sensor was constructed with the electrode prepared above as recognition element, and the response characteristics of the sensor to chlorpyrifos in water were investigated based on constant-current potentiometry. It was shown that a reasonable linear response curve between potential and concentration was obtained from 1.0×10-12mol/L to 2.0×10-8mol/L, with a detection limit of 1.0×10-13mol/L. The suitable pH was 2.2~3.4,and response time was 10 min. The imprinted electrode showed relatively high selectivity to chlorpyrifos and was applied to the analysis of chlorpyrifos in the simulated river samples with recovery rates ranging from 89% to 105%.

A Sensitive Formaldehyde Sensor Based on Cataluminescence Coupled with Thermal Desorption

2014 ◽  
Vol 670-671 ◽  
pp. 1163-1166 ◽  
Author(s):  
Hong Wei Yang ◽  
Zheng Xing ◽  
Kao Wen Zhou
Keyword(s):  
Detection Limit ◽  
Thermal Desorption ◽  
Flow Rate ◽  
Active Carbon ◽  
Room Temperature ◽  
High Selectivity ◽  
Formaldehyde In Air ◽  
Benzene Toluene ◽  
Versus Concentration

A sensitive cataluminescence-based detecting technology using nanosized Mo4V6Ti10O47 as a probe was proposed for determination of formaldehyde in air. Trace formaldehyde was firstly absorbed on active carbon at room temperature to concentrate, then desorbed at 75°C to determine. The method showed high selectivity to formaldehyde at wavelength of 575nm, satisfying activity at temperature of 260°C and good stability at carrier flow rate of 145 ml/min. The linear range of CTL intensity versus concentration of formaldehyde was 0.04~78 mg/m3, and the detection limit (3σ) was 0.02 mg/m3. The recovery of artificial sample was 96.8%-103.4% by this method. There was no response to CO, CO2, SO2, NH3, methanol, ethanol, benzene, toluene and xylenes.

scholarly journals Neodymium(III) PVC Membrane Electrodchemical Sensor Based on N-benzoylethylidene-2-aminobenzylamine

2012 ◽  
Vol 9 (4) ◽  
pp. 1941-1950 ◽  
Author(s):  
Hassan Ali Zamani ◽  
Mojdeh Zaferoni ◽  
Soraia Meghdadi
Keyword(s):  
Alkaline Earth ◽  
High Selectivity ◽  
Pvc Membrane ◽  
Indicator Electrode ◽  
Solution Ph ◽  
Response Characteristics ◽  
Potentiometric Response ◽  
Nernstian Slope ◽  
Mouth Wash

The N-benzoylethylidene-2-aminobenzylamine (BEA) was used as a suitable ionophore in construction of neodymium ion selective electrode. The electrode with composition of 30% PVC, 58% solvent mediator (NB), 2% ionophore (BEA) and 10% anionic additive (OA) shows the best potentiometric response characteristics. The Nd3+sensor exhibits a Nernstian slope of 21.2 ± 0.2 mV decade-1over the concentration range of 1.0 × 10-6to 1.0 × 10-2mol L-1, and a detection limit of 6.3 × 10-7mol L-1of Nd3+ions. The potentiometric response of the sensor is independent of the solution pH in the range of 2.4–8.5. It has a very short response time, in the whole concentration range (~7 s), and can be used for at least eight weeks. The proposed sensor revealed high selectivity with respect to all common alkali, alkaline earth, transition and heavy metal ions, including members of the lanthanide family other than Nd3+. The Nd3+sensor was successfully applied as an indicator electrode in the potentiometric titration of Nd3+ions with EDTA. The electrode was also employed for the determination of the fluoride ion in two mouth wash preparations.

A chemiluminescence sensor for determination of lysozyme using magnetic graphene oxide multi-walled carbon nanotube surface molecularly imprinted polymers

RSC Advances ◽  
2016 ◽  
Vol 6 (15) ◽  
pp. 12391-12397 ◽  
Author(s):  
Yanhui Wang ◽  
Huimin Duan ◽  
Leilei Li ◽  
Xiaojiao Wang ◽  
Jianbo Li ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Carbon Nanotube ◽  
Molecularly Imprinted Polymers ◽  
High Selectivity ◽  
Imprinted Polymer ◽  
Magnetic Graphene Oxide ◽  
Molecularly Imprinted ◽  
Magnetic Graphene ◽  
Multi Walled Carbon Nanotube

In this paper, a new chemiluminescence sensor possessing high selectivity and sensitivity was established for determination of lysozyme using magnetic graphene oxide–multi-walled carbon nanotube surface molecularly imprinted polymer.

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