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Now showing items 21-30 of 68
Radon concentration determination in some dwellings of Doha city of Qatar
(
Elsevier
, 1997 , Article)
Yearly average radon concentrations have not been reported yet in Qatar. Only few measurements on indoor radon concentrations have been conducted during the autumn season in 1992. To complete these measurements a determination ...
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 ...
Positron annihilation lifetime study of pure and treated polyvinyl chloride
(
scientific.net
, 1997 , Article)
Positron annihilation lifetime technique (PAL) has been applied to investigate the behavior of the free volume in pure and doped polyvinyl chloride (PVC) as a function of Pb concentration and temperature. It is noticed ...
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 ...
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). ...
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 ...
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 ...
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 ...
(−)-Paniculatol, a new ent-labdane bromoditerpene from Laurencia paniculata
(
Elsevier Science Ltd.
, 1997 , Article)
(−)-Paniculatol, 1, an unusual tricyclic bromoditerpene belonging to the ent-labdane series has been identified in the red alga Laurencia paniculata collected on Qatari coasts, Arabian Gulf. The structure displays an unusual ...
Constituents of plants growing in Qatar XVII anti-inflammatory and cytotoxic activities of extracts of thirty indigenous species
(
Taylor & Francis
, 1990 , Article)
Thirty plants, indigenous to Qatar, were extracted separately with hexane, chloroform and ethanol. The dried extracts were examined for potential anti-inflammatory activities both in vitro by their ability to inhibit ...