Electrochemical Cyclization of Adrenaline, the Simplest Derivatization for its Selective Determination

2017 ◽  
Vol 29 (9) ◽  
pp. 2004-2007 ◽  
Author(s):  
Mohammad Rafiee ◽  
Lida Khalafi ◽  
Fatemeh Mousavi ◽  
Fatemeh Babaloii ◽  
Fatemeh Kalhori
Keyword(s):  
Selective Determination ◽  
Electrochemical Cyclization

Selective determination of non-biodegradable polar, organic pollutants in waste water related to functional groups using flow injection combined with tandem mass spectrometry

1996 ◽  
Vol 34 (7-8) ◽  
pp. 21-28 ◽  
Author(s):  
H. Fr. Schröder
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Functional Groups ◽  
Organic Pollutants ◽  
Molar Mass ◽  
Sewage Treatment ◽  
Tandem Mass ◽  
Screening Process ◽  
Selective Determination ◽  
Characteristic Fragment

Effluents of biological sewage treatment plants mainly contain non-biodegradable, polar, organic pollutants of biogenic and anthropogenic origin. This paper presents a substance-specific determination method for these compounds, which are partly able to reach drinking water during the soil filtration process. Tandem mass spectrometry (MS/MS) combined with softly ionizing interfaces is applied for this purpose. The behaviour of the functional groups of these pollutants - forming characteristic fragment ions under MS/MS conditions and abstracting neutral particles - is used for detection. With help from this screening process on specific functional groups it is possible to establish the presence of substance groups with similar behaviour in the aquatic environment. Additionally this analytical procedure provides information on the molar mass of the pollutants detected. In a second step the compounds characterized by the molar mass and belonging to a group of pollutants with specific functional groups can be identified using MS/MS.

Laser optoacoustic detection of trace concentration levels of ethylene, vinylchloride, and styrene in the atmosphere

1989 ◽  
Vol 54 (10) ◽  
pp. 2667-2673 ◽  
Author(s):  
Vojtěch Steiner ◽  
Pavel Engst ◽  
Zdeněk Zelinger ◽  
Milan Horák
Keyword(s):  
Detection Limit ◽  
Emission Line ◽  
Laser Line ◽  
Laser Source ◽  
Trace Concentration ◽  
Selective Determination ◽  
Hygienic Standard ◽  
Trace Concentrations ◽  
Concentration Levels

The optoacoustic analyzer with a tunable CO2 laser source employed in the present work permits a selective determination of ethylene in trace concentrations higher than 5 ppb (=detection limit for the 10P(14) emission line of the CO2 laser, ν = 949.5 cm-1) and of vinylchloride higher than 42 ppb (= detection limit for the 10P(22) CO2 laser line, ν= 942.4 cm-1). this method covers for both compounds the concentration range corresponding to the hygienic standard. It can be also used for the determination of styrene vapour with concentrations higher than 1.5 ppm.

Novel palladium(II) selective membrane electrode based on 4-[(5-mercapto-1,3,4-thiadiazol-2-ylimino)methyl]benzene-1,3-diol

2010 ◽  
Vol 75 (5) ◽  
pp. 563-575 ◽  
Author(s):  
Moslem Mohammadi ◽  
Mehdi Khodadadian ◽  
Mohammad K. Rofouei
Keyword(s):  
Limit Of Detection ◽  
Membrane Electrode ◽  
Aqueous Samples ◽  
Selective Determination ◽  
Poly Vinyl Chloride ◽  
Selective Membrane ◽  
Ph Range ◽  
Palladium Content ◽  
Methyl Benzene

A plasticized poly(vinyl chloride) membrane electrode based on 4-[(5-mercapto-1,3,4-thiadiazol-2-ylimino)methyl]benzene-1,3-diol (L) for highly selective determination of palladium(II) (in PdCl42– form) is developed. The electrode showed a good Nernstian response (29.6 ± 0.4 mV per decade) over a wide concentration range (3.1 × 10–7 to 1.0 × 10–2 mol l–1). The limit of detection was 1.5 × 10–7 mol l–1. The electrode has a response time of about 20 s, and it can be used for at least 2 months without observing any considerable deviation from Nernstian response. The proposed electrode could be used in the pH range of 2.5–5.5. The practical utility of the electrode has been demonstrated by its use for the estimation of palladium content in aqueous samples.

scholarly journals Expert System for Catalytic Titrimetry—Part 2: Determination of Monobasic Carboxylic Acids

1998 ◽  
Vol 81 (5) ◽  
pp. 1077-1086
Author(s):  
Biljana F Abramovic ◽  
Borislav K Abramovic ◽  
Ferenc F Gaál ◽  
Danilo M Obradovtc
Keyword(s):  
Expert System ◽  
Carboxylic Acids ◽  
Selective Determination

Abstract An expert system (ES) to solve the problem of choosing a catalytic titrimetric procedure for determining monobasic carboxylic acids is described. Carboxylic acids were divided into 3 groups—aliphatic, aromatic, and α-aminocarboxylic acids— based on their behavior in catalytic titrations with different indicator reactions, titrant, and/or solvent and the possibility of their selective determination in the presence of other acids

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 A novel luminol chemiluminescence induced by photoexcited ketones: A selective determination method for acetone in wastewater

Talanta Open ◽  
2021 ◽  
Vol 3 ◽  
pp. 100035
Author(s):  
Hitoshi Kodamatani ◽  
Daisuke Yoshimine ◽  
Takahiro Fujioka ◽  
Ryo Kanzaki ◽  
Takashi Tomiyasu
Keyword(s):  
Determination Method ◽  
Selective Determination ◽  
Luminol Chemiluminescence
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