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1.
J Sep Sci ; 39(18): 3638-46, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27440123

ABSTRACT

Analytical methods based on multiplug filtration cleanup coupled with pulse glow discharge-ion mobility spectrometry and liquid chromatography tandem mass spectrometry were developed for the analysis of tricaine mesylate residue in fish and fish-raising water samples. A silica fiber holder and an appropriate new interface were designed to make the direct introduction of the fiber into the pulse glow discharge-ion mobility spectrometry introduction mechanism. The multiplug filtration cleanup method with adsorption mixtures was optimized for the determination of tricaine mesylate in fish samples. Good linear relationships were obtained by the two methods. For fish samples, limits of detection were 6 and 0.6 µg/kg by ion mobility spectrometry and liquid chromatography with tandem mass spectrometry, respectively. The matrix effect of the established liquid chromatography tandem mass spectrometry method was negligible for fish samples but that of the ion mobility spectrometry method was not. The two methods were compared. The ion mobility spectrometry system could be used a rapid screening tool on site with the advantage of rapidity, simplicity, and portability, and the liquid chromatography tandem mass spectrometry system could be used for validation in laboratory conditions with the advantage of lower limit of detection, stability, and precision.


Subject(s)
Aminobenzoates/analysis , Chromatography, Liquid/methods , Filtration/methods , Ion Mobility Spectrometry/methods , Mesylates/analysis , Pesticide Residues/analysis , Tandem Mass Spectrometry/methods , Water Pollutants, Chemical/analysis , Aminobenzoates/isolation & purification , Animals , Fishes , Limit of Detection , Mesylates/isolation & purification , Seafood/analysis , Water Pollutants, Chemical/isolation & purification
2.
Chemosphere ; 138: 988-94, 2015 Nov.
Article in English | MEDLINE | ID: mdl-25563159

ABSTRACT

The photocatalytic degradation of the herbicide sulcotrione (0.05 mM) and its formulated compound Tangenta® in aqueous suspensions of TiO2 Degussa P25 was examined as a function of the different operational parameters. The optimum of the catalyst loading was found to be 2.0 mg mL(-1) under UVA light. In the first stage of the reaction, the photocatalytic degradation of sulcotrione alone and in Tangenta® followed the pseudo-first order kinetics, in which the heterogeneous catalysis proceeds via OH and holes. Further, it can be concluded that degradation rate of sulcotrione alone is about two times higher compared to formulated compound. The results showed that the disappearance of sulcotrione led to the formation of three organic intermediates and ionic byproducts (Cl(-), SO4(2-), acetate and formate), whereas their mineralization was about 90% after 4 h. Tentative photodegradation pathways were proposed and discussed. Also, there was no significant toxicity observed after the irradiation of sulcotrione solution and Tangenta® formulation using TiO2 catalyst on three mammalian cell lines.


Subject(s)
Cyclohexanones/isolation & purification , Light , Mesylates/isolation & purification , Photolysis , Titanium/chemistry , Water Pollutants, Chemical/isolation & purification , Water Purification/methods , Animals , Catalysis , Cell Line , Cell Survival/drug effects , Cyclohexanones/radiation effects , Cyclohexanones/toxicity , Humans , Kinetics , Mesylates/radiation effects , Mesylates/toxicity , Solutions , Suspensions , Water Pollutants, Chemical/radiation effects , Water Pollutants, Chemical/toxicity
3.
Appl Radiat Isot ; 94: 141-146, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25189703

ABSTRACT

The [(18)F]fluoroethyl moiety has been widely utilized in the synthesis of (18)F-labelled compounds. The aim of this work was the reliable synthesis of [(18)F]FEtOTf with a novel strategy to increase the reactivity of the commonly used [(18)F]FEB and [(18)F]FEtOTos. [(18)F]FEtOTf and the intermediate [(18)F]FEtOH were synthesized in high RCY (78% and 85%, respectively) and purified by SPE. The high potency of [(18)F]FEtOTf was shown by the efficient alkylation of the deactivated nucleophile aniline under mild conditions, as well as by the synthesis of [(18)F]FEC.


Subject(s)
Fluorine Radioisotopes/chemistry , Fluorine Radioisotopes/isolation & purification , Isotope Labeling/methods , Mesylates/chemical synthesis , Mesylates/isolation & purification , Radiopharmaceuticals/chemical synthesis , Radiopharmaceuticals/isolation & purification , Vinyl Compounds/chemistry
4.
Nat Protoc ; 8(6): 1042-7, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23640168

ABSTRACT

The present protocol details the synthesis of zinc bis(alkanesulfinate)s that can be used as general reagents for the formation of radical species. The zinc sulfinates described herein are generated from the corresponding sulfonyl chlorides by treatment with zinc dust. The products may be used crude, or a simple purification procedure may be performed to minimize incorporation of water and zinc chloride. Although the synthesis of the zinc sulfinate salts can generally be completed within 3 h, workup can take up to 24 h and purification can take up to 3 h. Following the steps in this protocol would enable the user to generate a small toolkit of zinc sulfinate reagents over the course of 1 week.


Subject(s)
Alkanesulfonates/chemistry , Alkanesulfonates/isolation & purification , Drug Discovery/methods , Mesylates/chemistry , Mesylates/isolation & purification , Molecular Structure , Sulfinic Acids/chemistry , Zinc/chemistry
5.
J Pharm Biomed Anal ; 55(1): 220-4, 2011 Apr 28.
Article in English | MEDLINE | ID: mdl-21277726

ABSTRACT

A enantioselective reversed-phase high performance liquid chromatographic method was developed for the enantiomeric resolution of safinamide mesilate, 2(S)-[4-(3-fluorobenzyloxy)benzylamino] propionamide methanesulfonate, a neuroprotectant with antiparkinsonian and anticonvulsant activity for the treatment of Parkinson disease. The enantiomers of safinamide mesilate were baseline resolved on a Chiralcel OD-RH (150mm×4.6mm, 5µm) column using a mobile phase system containing 300mM sodium di-hydrogen phosphate buffer (pH 3.0):methanol:acetonitrile (65:25:10, v/v/v). The resolution between the enantiomers was not less than 3.0. The pH value of buffer solution in the mobile phase has played a key role in enhancing chromatographic efficiency and resolution between the enantiomers. The developed method was validated and proved to be robust. The limit of detection and limit of quantification of (R)-enantiomer were found to be 15 and 50ng/mL, respectively, for 20µL injection volume. The percentage recovery of (R)-enantiomer was ranged from 94.2 to 103.7 in bulk drug samples of safinamide mesilate. The sample solution and mobile phase were found to be stable at least for 48h. The final optimized method was successfully applied to separate (R)-enantiomer from safinamide mesilate and was proven to be reproducible and accurate for the quantitative determination of (R)-enantiomer in bulk drugs.


Subject(s)
Alanine/analogs & derivatives , Antiparkinson Agents/isolation & purification , Benzylamines/isolation & purification , Mesylates/isolation & purification , Monoamine Oxidase Inhibitors/isolation & purification , Technology, Pharmaceutical , Alanine/analysis , Alanine/chemistry , Alanine/isolation & purification , Antiparkinson Agents/analysis , Antiparkinson Agents/chemistry , Benzylamines/analysis , Benzylamines/chemistry , Calibration , Cellulose/analogs & derivatives , Cellulose/chemistry , Chromatography, High Pressure Liquid , Drug Contamination/prevention & control , Drug Stability , Hydrogen-Ion Concentration , Limit of Detection , Mesylates/analysis , Mesylates/chemistry , Monoamine Oxidase Inhibitors/analysis , Monoamine Oxidase Inhibitors/chemistry , Parkinson Disease/drug therapy , Phenylcarbamates/chemistry , Quality Control , Reproducibility of Results , Stereoisomerism
6.
J Pharm Biomed Anal ; 52(4): 603-8, 2010 Aug 01.
Article in English | MEDLINE | ID: mdl-20138458

ABSTRACT

10-O-(N,N-dimethylaminoethyl)-ginkgolide B methanesulfonate (XQ-1H), a novel active derivative of ginkgolide B, is a platelet-activating factor antagonist which is being under clinical trial. Two unknown related impurities were observed in analysis of XQ-1H bulk drug. A scaling up preparative liquid chromatography (Prep LC) was used for isolation of the two impurities. Based on LC-MS/MS and nuclear magnetic resonance (NMR) spectra, they were characterized as 10-O-(N,N-dimethylaminoethyl)-11,12-seco-ginkgolide B (imp-1) and 10-O-(N,N-dimethylaminoethyl)-11,12,2,15-diseco-3,14-dehydroginkgolide B (imp-2), respectively. A reversed-phase liquid chromatography (RP-LC) was developed for simultaneous determination of XQ-1H as well as imp-1 and imp-2. Main variables that significantly influence the chromatographic procedure were optimized and efficient chromatographic separation was achieved on a CN column with mobile phase consisting of 5mM dipotassium hydrogen phosphate (pH 7.5) and methanol delivered in a gradient mode at the flow rate of 1.0mLmin(-1). The method was validated and found to be suitable to check the quality of bulk samples of XQ-1H at test concentration of 5.0mgmL(-1) for a 20microL injection volume.


Subject(s)
Chromatography, Reverse-Phase/standards , Drug Contamination , Ethylamines/isolation & purification , Ginkgolides/isolation & purification , Lactones/isolation & purification , Mesylates/isolation & purification , Chromatography, Liquid/methods , Chromatography, Liquid/standards , Chromatography, Reverse-Phase/methods , Ethylamines/chemistry , Ginkgolides/chemistry , Lactones/chemistry , Mesylates/chemistry
7.
J Chromatogr Sci ; 46(4): 316-9, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18402722

ABSTRACT

In this study, several thin-layer chromatography (TLC) methods are described for the identification of quaternary and non-quaternary compounds (parent compounds, intermediates, by-products, and products) arisen within the synthesis of the acetylcholinesterase reactivator HI-6, at present the most promising antidote in the case of nerve agent poisonings. Using the TLC technique, particular E and Z isomers of this compound on the oxime group are separated. These TLC methods could be of high interest as quick purity control for those who are interested in development of new acetylcholinesterase reactivators and the synthesis of HI-6 in laboratories or in large-scale production.


Subject(s)
Chromatography, Thin Layer/methods , Mesylates/isolation & purification , Oximes/isolation & purification , Pyridinium Compounds/chemical synthesis , Cholinesterase Reactivators/chemical synthesis , Cholinesterase Reactivators/isolation & purification , Pyridinium Compounds/isolation & purification
9.
J Chromatogr A ; 918(2): 429-33, 2001 May 25.
Article in English | MEDLINE | ID: mdl-11407590

ABSTRACT

This paper assesses the effect of pressurised fluid extraction (PFE) on the recovery of bupirimate and its degradation product, ethirimol from a range of soil types. The analytes were extracted under standard conditions (pressure, 2000 p.s.i.; temperature, 100 degrees C; and, three static flush cycles of 5 min static extraction time each) using a variety of individual and combined solvents. It was found that the recovery of bupirimate was dependent upon the organic matter content of soil.


Subject(s)
Mesylates/isolation & purification , Pyrimidinones/isolation & purification , Soil Pollutants/isolation & purification , Gas Chromatography-Mass Spectrometry , Pressure
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