Chemistry & Earth Sciences: المرسلات الحديثة
السجلات المعروضة 121 -- 140 من 587
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Selective determination of thiamine (vitamin B1) in pharmaceutical preparations by direct potentiometric argentometric titration with use of the silver-silver sulphide ion-selective electrode
( Elsevier , 1989 , Article)A simple and selective argentometric titration method is described for determination of thiamine (vitamin B1), based on direct potentiometric titration in alkaline media (⩾0.5M) in which a chemical transformation takes ... -
Liquid membrane electrodes for the selective determination of nicotine in cigarette smoke
( The Royal Society of Chemistry , 1989 , Article)Five liquid membrane electrode systems responsive to the nicotinium cation are described. These electrodes are based on the use of the ion-association complexes of the nicotinium cation with tetraphenylborate, 5-nitrobarbiturate, ... -
Solid-state planar microsensors for selective potentiometric determination of ethylmorphine
( Marcel Dekker Inc. , 1999 , Article)The potentiometric performance characteristics of microelectronically fabricated solid-state planar ethylmorphine sensors based on silicon/silicon nitride substrate and a mixture of ethylmorphine-tetraphenylborate and ... -
Spectrophotometric Determination of Hydrogen Peroxide by a Hydroquinone-Aniline System Catalyzed by Molybdate
( Korean Chemical Society , 2004 , Article)In this system hydroquinone is oxidized to pbenzoquinone by H2O2. 2 aniline are added, in successive stages, to pbenzoquinone, to yield the disubstituted quinone as the final product. 20 The UV-VIS spectrum of the product ... -
Thiamine-reineckate liquid membrane electrode for the selective determination of thiamine (vitamin B1) in pharmaceutical preparations
( The Royal Society of Chemistry , 1989 , Article)The construction and electrochemical response characteristics of a liquid membrane electrode for thiamine (vitamin B1) based on the formation of an ion pair between the thiamine cation and the reineckate anion in nitrobenzene ... -
Poly(vinyl chloride) matrix membrane electrodes for manual and flow injection determination of metal azides
( The Royal Society of Chemistry , 1992 , Article)Novel poly(vinyl chloride) matrix membrane electrodes for the azide ion are developed, electrochemically evaluated and used for manual and flow injection determinations of soluble and insoluble metal azides. These electrodes ... -
Nitron tetrachloroaurate(III) electrodes with poly(vinyl chloride) and liquid membranes for the selective determination of gold
( Elsevier , 1991 , Article)PVC matrix and liquid membrane electrodes have been developed for direct potentiometric determination of gold(III). The membranes incorporate nitron tetrachloroaurate(III) as electroactive material. Fast response for ... -
Determination of amitriptyline, imipramine and orphenadrine in antidepressant drugs by potentiometry, spectrophotometry and atomic absorption spectrometry
( Springer-Verlag , 1993 , Article)Methods are described for the determination of amitriptyline, imipramine and orphenadrine in some antidepressant drugs. They are based on a prior reaction with ammonium reineckate to form 1∶1 water-insoluble drugreineckate ... -
Liquid and poly (vinyl chloride) matrix membrane electrodes for the selective determination of cocaine in illicit powders
( Elsevier , 1992 , Article)The construction of liquid membrane and PVC matrix-type cocainium ion selective electrodes and their use for direct potentiometry and potentiometric titration of cocaine are described. The ion-pair complexes of cocaine ... -
Determination of glafenine in dosage forms and serum by thin layer densitometry and high performance liquid chromatography
( Elsevier , 1997 , Article)New thin layer densitometry and high performance liquid chromatography (HPLC) methods are described for quantitative determination of glafenine in dosage forms in the presence of its photo-degradation products and in serum ... -
Plastic Membrane Electrodes for the Potentiometric Determination of Codeine in Pharmaceutical Preparations
( Springer New York , 1997 , Article)Four PVC membrane electrode systems responsive to codeinium cation are described. These electrodes are based on the use of the ion-association complexes of the codeinium cation with tetraphenylborate and reineckate ... -
Mercurimetric potentiometric determination of barbiturates using a solid-state iodide ion-selective electrode
( Taylor and Francis Inc. , 1997 , Article)A simple potentiometric method is described for mercurimetric titration of barbiturates using a solid-state iodide ion-selective electrode. The optimum titration conditions involve the use of a borate buffer of pH 9-10 as ... -
A New Poly (Vinyl Chloride) Matrix Membrane Electrode for Manual and Flow Injection Determination of Pilocarpine in Some Pharmaceutical Preparations
( Taylor and Francis Inc. , 1994 , Article)A novel pilocarpinium ion selective membrane electrode is prepared, characterized and used in pharmaceutical analysis. The electrode system incorporates a PVC membrane with pilocarpine-reineckatc ion pair complex as an ... -
Kinetic Determination of Morphine in Illicit Powders, Using a Fluoride Selective Electrode, Based on Reaction with 1-Fluoro-2,4-dinitrobenzene
( Springer New York , 1996 , Article)A simple, accurate and selective method is described for the determination of morphine in illicit powders, based on monitoring the initial rate of fluoride ion liberation from the reaction of morphine with 1-fluoro-2,4-d ... -
Novel thorium membrane sensors with anionic response based on trioctylphosphine oxide and toluate ionophores
( Wiley-VCH Verlag , 2008 , Article)Two novel potentiometric polymeric membrane sensors for rapid and accurate determination of thorium are described. These are based on the use of trioctylphosphine oxide (TOPO) and thorium toluate (Th-TA) as ionophores ... -
Novel biomedical sensors for flow injection potentiometric determination of creatinine in human serum
( Wiley-VCH Verlag , 2005 , Article)Coated-wire (CW) and tubular (Tu) type membrane sensors for creatinine are developed. These consist of creatinine tungstophosphate(CTP), creatinine molybdophosphate (CMP) and creatinine picrolonate (CPC) ion-pair complexes ... -
Continuous potentiometric monitoring of viagra (sildenafil) in pharmaceutical preparations using novel membrane sensors
( Springer Nature , 2006 , Article)Two potentiometric sensors responsive to sildenafil citrate (SC) drug (the active component of viagra) are described, characterized, compared and used for drug assessment. The sensors are based on the use of the ion-association ... -
Novel potentiometric copper (II) selective membrane sensors based on cyclic tetrapeptide derivatives as neutral ionophores
( Elsevier , 2005 , Article)Two novel membrane sensors sensitive and reasonably selective for Cu2+ ions are described. These are based on the use of newly synthesized cyclic tetrapeptide derivatives as neutral ionophores and sodium tetraphenylborate ... -
Constituents of plants growing in Qatar part XV. Chemical investigation and pharmacotoxicity of pyrrolizidine alkaloids of moltikiopsis ciliata
( Taylor & Francis , 1988 , Article)Chemical study of the alkaloidal constituents of Moltikiopsis ciliata resulted in the isolation and identification of heliotrine and echinatine, in addition to other minor alkaloids. Pharmacological experiments revealed: ... -
Poisonous plants contaminating edible ones and toxic substances in plant foods IV. Phytochemistry and toxicity of lolium temulentum
( Taylor & Francis , 2008 , Article)Different procedures were carried out for the preparation and separation of the total alkaloids of Lolium temulentum. Loline has been identified as the major pyrrolizidine alkaloid of the seeds. The toxicity of the alcoholic ...