Chemistry & Earth Sciences: المرسلات الحديثة
السجلات المعروضة 81 -- 100 من 543
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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 ... -
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 ... -
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 ... -
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 ... -
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 ... -
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 ... -
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 ... -
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 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 ... -
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 ... -
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 ... -
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 ... -
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 ... -
Constituents of plants growing in Qatar - Part XIX. Flavonoids of Glossonema edule N. E. Br.
( Springer Nature , 1990 , Article)The study of the flavonoids of the unripe fruits of Glossonema edule, resulted in the isolation and identification of apigenin 6,8-di-C-glucoside (violanthin) and luteolin 7-O-glucoside. © 1990 Kluwer Academic Publishers. -
Constituents of plants growing in Qatar XX. Phytochemical investigation of anastatica hierochuntica: NOTE
( Taylor & Francis , 1993 , Article)A study of the lipid fraction of Anastatica hierochuntica (Cruciferae) resulted in the isolation of hydrocarbon (mainly C25H52, C29H60 AND C31H64) AND sterol fractions (P-sitosterol, campesterol, stigmasterol AND cholesterol). ... -
Sesquiterpene lactones from Pulicaria sicula
( Elsevier , 1988 , Article)The aerial parts of Pulicaria sicula afforded the known xanthanolides 1-6, the guaianolides 7 and 8 as well as two new ones, the lactone 9 and the corresponding epoxide 10. Furthermore nerylisobutyrate and the thymol ... -
Development of Inorganically Cross-Linked Sulfonated Polyacrylamide Preformed Particle Gels for Conformance Control: Impact of Anionic Groups
( American Chemical Society (ACS) , 2024 , Article)Modern oil and gas extraction faces challenges, notably from the surplus of produced water, hampering hydrocarbon recovery and raising environmental and economic concerns. A promising solution is the injection of preformed ...