http://blogs.najah.edu/author/nidalzatar An-Najah Blogs :: Nidal Zatar en-us Thu, 18 Apr 2024 07:42:17 IDT Thu, 18 Apr 2024 07:42:17 IDT [email protected] [email protected] http://blogs.najah.edu/staff/nidalzatar/article/Dye-effect-in-TiO2-catalyzed-contaminant-photo-degradation-Sensitization-vs-charge-transfer-formalismPublished ArticlesAnatase TiO2 surfaces have been treated with 246-triphenylpyrilium hydrogen sulfate TPPHS dye to yield the modified TiO2TPPHS surface The modified TiO2TPPHS surface was then supported onto activated carbon AC surfaces to yield a new class of catalytic system ACTiO2TPPHS The catalytic activities of naked TiO2 TPPHS solution TiO2TPPHS and ACTiO2TPPHS systems were examined in photo-degradation of phenol and benzoic acid in water using both UV and visible regions All studied systems showed low catalytic activity when used in the visible region In UV the ACTiO2TPPHS showed highest activity whereas the naked TiO2 and TPPHS solutions were the least active systems The dye role in enhancing activity of modified surfaces in UV degradation of contaminants is understandable by a charge-transfer catalytic effect rather than a sensitizing effect AC role is explainable by its ability to adsorb contaminant molecules and bringing them closer to catalytic sites Solid State Sciences Volume 9 Issue 1 January 2007 Pages 9-15 http:dxdoiorg101016jsolidstatesciences200610001http://blogs.najah.edu/staff/nidalzatar/article/Simultaneous-Determination-of-Seven-Synthetic-Water-Soluble-Food-Colorants-by-Ion-Pair-Reversed-Phase-High-Performance-Liquid-ChromatographyPublished ArticlesA selective gradient ion-pair reversed-phase high-performance liquid chromatographic method for the simultaneous quantitative determination of seven synthetic water-soluble food colorants Tartrazine E102 Quinoline Yellow E104 Sunset Yellow E110 Carmoisine E122 Ponceau 4R E124 Erythrosine E127 Carmine E132 and Brilliant Blue FCF E133 was developed Analysis were performed on 12546 mm id Merck Lichrosher 100 RP C-18 5 m column The flow rate of the mobile phase was 10 mL min 1 and the injection volume was 50 L The mobile phase consisted of water:acetonitrile 50:50 v v 1 Containing 035 M 1-Hexadecyl Trimethylammonium Bromide CTAB and buffered to pH 75 mobile phase A and water acetonitrile 50:50 v v 1 mobile phase B Successful separation and quantitative determination was obtained for all the colorants using an optimized gradient elution program Detection limits were 159 E142 and 221 E124 ppm with relative standard deviations in the range 037 The method was applied to the determination of colorants in various types of drinks and food such as carbonated fruit flavored drinks concentrated fruit flavored drinks jams and sugar confectionery http://blogs.najah.edu/staff/nidalzatar/article/Quantitative-Determination-of-Three-Textile-Reactive-Dyes-lrmin-Ground-Water-Sewage-Water-and-Soil-Using-lrmVoltammetric-and-HPLC-TechniqueslrmPublished ArticlesDifferential-pulse adsorptive cathodic stripping voltammetric DP-AdCSV and high performance liquid chromatography HPLC techniques were developed for quantitative determination of Reactive Blue 19 Reactive Red 198 and Reactive Orange 107 textile dyes The calibration curves using the DP-AdCSV method were found to be linear over the ranges 005-10 ppm 010-110 ppm and 005-10 ppm respectively The HPLC method is based on using a mobile phase consisting of acetonitrile:water 60:40 vv containing 045 M N-Cetyl-NNN-trimethylammonium bromide CTAB and buffered to pH 792 Reverse phase RP C18 column was used with a flow rate of 06 mlminute The retention times for Reactive Blue 19 Reactive Red 198 and Reactive Orange 107 were found to be 54 min 78 min and 23 min respectively The calibration curves were found to be linear over the ranges 01-50 ppm 01-12 ppm and 005-15 ppm respectively An-Najah University Journal for Research - Natural Sciences A ISSN: 1727-2114 Volume 18 Issue 2 2004 Pages: 173-192http://blogs.najah.edu/staff/nidalzatar/article/Spectrophotometric-Determination-of-Tiopronin-in-Pharmaceutical-PreparationsPublished ArticlesTwo spectrophotometric methods are described for the determination of tiopronin in pharmaceuticals They are based on the oxidation-reduction reaction between tiopronin and iron III then forming a complex between iron II and ferrozine or di-2-pyridyl ketone-2-thiophenoylhydrazone The produced colored iron II-ferrozine complex [system I] absorbs at 562 nm while the iron II-di-2-pyridyl ketone-2-thiophenoylhydrazone complex [system II] absorbs at 656 nm The effect of different factors such as: pH reagent concentration time of reaction temperature and the tolerance amount of the common excipients have been studied Applying the optimum working conditions tiopronin can be determined over the range 02-86 and 05-170 ppm and with molar absorptivities of 20x104 and 10x104 l mol-1cm-1 for systems I and II respectively Both methods offer high selectivity sensitivity and accuracy with a relative standard deviation RSD of less than 11 for five measurements The proposed methods were applied successfully for the determination of tiopronin in Captimer tablets Key Words: Spectrophotometry Tiopronin Ferrozine Di-2-pyridyl ketone-2-Thiophenoylhydrazone DPKTH Pharmaceutical analysis An-Najah University Journal for Research - Natural Sciences A ISSN: 1727-2114 Volume 15 2001 Pages: 145-157http://blogs.najah.edu/staff/nidalzatar/article/Voltammetric-and-Spectrophotometric-Determination-of-Nizatidi-ne-in-Pharmaceutical-FormulationsPublished ArticlesTwo methods are described for quantitative determination of nizatidine The first is a cathodic stripping voltammetric method which is based on the accumulation of the compound at the hanging mercury drop electrode The adsorptive stripping response was evaluated with respect of accumulation time potential concentration pH and other variables A linear calibration graph was obtained over the range 3010810106M with a detection limit 30108M after a 20s accumulation time at 02V accumulation potential On the other hand it was found that the detection limit could be lowered to 10108M after 180s accumulation time at 02V accumulation potential The relative standard deviation was in the range 1220 for six measurements The tolerance amounts of the common excipients have also been reported The second is a spectrophotometric method which is based on the formation and extraction of the ion-pair complex formed between nizatidine and either bromocresol green or bromothymol blue The extracted colored ion-pair complexes absorb at 416nm The effect of different factors such as: type of organic solvent pH reagent concentration number of extraction times shaking time temperature and the tolerance amount of the common excipients have been reported The calibration graph was linear in the range 6010718105M with a detection limit of 60107M and molar absorptivity of 21104lċmol1ċcm1 when using bromocresol green while the calibration graph was linear in the range 3010711105M with a detection limit of 30107M and molar absorptivity of 32104lċmol1ċcm1 when using bromothymol blue The spectrophotometric methods offer alternative methods with reasonable sensitivity selectivity and accuracy with relative standard deviation in the range 2160 and 1247 for six measurements when using bromothymol blue and bromocresol green respectively The proposed two methods were applied for the determination of nizatidine in commercially available dosage forms A comparison between the voltammetric and the extraction-spectrophotometric methods was also reported Microchimica Acta Volume 134 Numbers 3-4 August 2000 http://blogs.najah.edu/staff/nidalzatar/article/Spectrophotometric-determination-of-nitrite-and-nitrate-using-phosphomolybdenum-blue-complex-Published ArticlesA method for spectrophotometric determination of nitrite and nitrate is described This method is based on the reduction of phosphomolybdic acid to phosphomolybdenum blue complex by sodium sulfide The obtained phosphomolybdenum blue complex is oxidized by the addition of nitrite and this causes a reduction in intensity of the blue color The absolute decrease in the absorbance of the blue color or the rate of its decrease is found to be directly proportional to the amount of nitrite added The absorbance of the phosphomolybdenum blue complex is monitored spectrophotometrically at 814 nm and related to the concentration of nitrite present The effect of different factors such as acidity stability of the complex time temperature phosphate concentration molybdenum concentration sodium sulfide concentration and the tolerance amount of other ions have been reported Maximum absorbance is at 814 nm The range of linearity using the conventional method is 0520 ppm with molar absorptivity of 11104 l mol1 cm1 and a relative standard deviation of 26 for five measurements The range of linearity using the reaction rate method is 0236 ppm with a relative standard deviation of 24 for five measurements The method is applied for determination of nitrite and nitrate in water meat products and vegetables Talanta Volume 50 Issue 4 15 November 1999 Pages 819-826 http://blogs.najah.edu/staff/nidalzatar/article/A-catalytic-method-for-the-determination-of-trace-amounts-of-mercury-uptaken-by-broad-beams-plantsPublished ArticlesA method for spectrophotometric determination of four aromatic amines is described The method is based on the reaction between the amine and the colorless FeIII-ferrozine complex The amine reduces iron from FeIII to FeII which forms a violet colored complex with ferrozine The method is suitable for to the determination of 14-phenylenediamine 24-diaminotoluene 8-aminoquinoline and 2-amino-3-hydroxypyridine The effect of different factors such as; pH stability of the complex temperature ferrozine concentration FeIII concentration and methanol concentration have been studied The composition of the complex as well as the tolerance amount of other amines have been reported Maximum absorbance is at 562 nm and Beers law is obeyed over the ranges 01716 ppm for 14-phenylenediamine 04537 ppm for 24-diaminotoluene 05134 ppm for 8-aminoquinoline and 05344 ppm for 2-amino-3-hydroxypyridine The obtained molar absorbtivities were 47104 20104 16104 15103 l mol1 cm1 respectively Talanta Volume 47 Issue 4 28 September 1998 Pages 883-890 http://blogs.najah.edu/staff/nidalzatar/article/Spectrophotometric-determination-of-some-aromatic-aminesPublished ArticlesA method for spectrophotometric determination of four aromatic amines is described The method is based on the reaction between the amine and the colorless FeIII-ferrozine complex The amine reduces iron from FeIII to FeII which forms a violet colored complex with ferrozine The method is suitable for to the determination of 14-phenylenediamine 24-diaminotoluene 8-aminoquinoline and 2-amino-3-hydroxypyridine The effect of different factors such as; pH stability of the complex temperature ferrozine concentration FeIII concentration and methanol concentration have been studied The composition of the complex as well as the tolerance amount of other amines have been reported Maximum absorbance is at 562 nm and Beers law is obeyed over the ranges 01716 ppm for 14-phenylenediamine 04537 ppm for 24-diaminotoluene 05134 ppm for 8-aminoquinoline and 05344 ppm for 2-amino-3-hydroxypyridine The obtained molar absorbtivities were 47104 20104 16104 15103 l mol1 cm1 respectively Talanta Volume 47 Issue 4 28 September 1998 Pages 883-890 http://blogs.najah.edu/staff/nidalzatar/article/Emodin-A-Naturally-Occuring-Anthraquinone-Its-Isolation-and-Spectrophotometric-Determination-in-Rumex-Cyprius-PlantPublished ArticlesA new method for isolation and specrophotometric determination of emodin is presented Emodin was isolated by thin layer chromatography tlc and column chromatography cc techniques as an orange long crystalline substance Emodin exhibits two absorption maxima at 420 and 520 nm Stability of the color and the effect of pH were studied Beers law is obeyed in the range 2-30 ppm The method is applied to the determination of emodin in roots stems and leaves of Rumex cyprius plant Spectroscopy Letters Volume 29 Issue 8 December 1996 pages 1539 - 1543http://blogs.najah.edu/staff/nidalzatar/article/A-Sensitive-Catalytic-Method-for-the-Determination-of-Copper-by-Its-Catalytic-Effect-on-the-Potassium-Bromate-Indigo-Carmine-Reaction-Published ArticlesA method for catalytic determination of copper II is presented The method is based on the catalytic effect of copperII on the rate of oxidation of indigo carmine by potassium bromate The method is satisfactory for the determination of copperII in the range 12 to 38 ngmL Effect of acidity indigo carmine potassium bromate temperature and tolerance limits of foreign ions are reported The method was applied to the determination of copper in synthetic and in various milk samples Instrumentation Science Technology Volume 22 Issue 4 November 1994 pages 355 - 363http://blogs.najah.edu/staff/nidalzatar/article/Donor-and-acceptor-number-effects-for-the-solvatochromic-behaviour-ofbis-22prime-bipyridyl-bis-cyanoironII-in-binary-aqueous-mixturesPublished ArticlesCorrelation with acceptor numbers was made for the solvatochromic behaviour ofbis-22-bipyridyl-bis-cyanoironII in binary aqueous mixtures of acetonitrile andDMF The relationship between isosolvation point and donor number of the organic cosolvent was proved to be linear Preferential solvation occurs by water in the case of the binary acetonitrile mixtures and byDMF in the case of the binaryDMF aqueous mixtures Monatshefte fr Chemie Chemical Monthly Volume 125 Numbers 6-7 June 1994 http://blogs.najah.edu/staff/nidalzatar/article/Plumbagin-a-Naturally-Occurring-Naphthoquinone-Its-Isolation-Spectrophotometric-Determination-in-Roots-Stems-and-Leaves-in-Plumbago-Europaea-LPublished ArticlesA new method for isolation and spectrophotometric determination of plumbagin is presented Plumbagin was isolated by thin layer chromatography TLC and column chromatography CC techniques as an orange tinged yellow long crystalline substances Plumbagin exhibits two absrop-tion maxima at 410 and 510 nm Stability of the color pKa value and the effect of pH were studied Beers law is obeyed over the range 09-45 ppm The method is applied to the determination of plumbagin in roots stems and leaves of Plumbago europaea L plant Spectroscopy Letters Volume 27 Issue 4 May 1994 pages 409 - 416http://blogs.najah.edu/staff/nidalzatar/article/Spectrophotometric-Determination-of-Uranium-with-Di-2-pyridyl-Ketone-BenzoylhydrazonePublished ArticlesA method for the spectrophotometric determination of uranium VI by complexation with Di-2-pyridyl ketone benzoylhydrazone DPKBH in 50 vv ethanolic solution is described Uranium VI forms a 1:2 complex with DPKBH The complex has a maximum absorbance at 377 um Beers law is obeyed over the range 0 2 - 12 ugm1 1 The effect of pH excess reagent percentage of ethanol vv stability of the complex and the tolerance limit of many metal ions and common anions have been reported The method has been applied to the determination of uranium in Egyptian monazite sandhttp://blogs.najah.edu/staff/nidalzatar/article/Spectrophotometric-Determination-of-Uranium-in-Ores-Using-Di-2-Pyridyl-Ketone-Hydrazone-DerivativesPublished ArticlesTwo methods for the spectrophotometric determination of uranium VI are described The methods are based on the formation of colored complexes for uranium VI with 1di-2-pyridyl ketone nicotinoylhydrazone DPKNH and 2di-2-pyridyl ketone thiophenoylhydrazone DPKTH in 50 vv ethanolic solution The complexes formed a uranium VI: complexing reagent mole ratio of 1:2 Maximum absorbance is at 373 nm for UVIDPKNH and at 389 nm for UVI - DPKTH Ranges of linearity effect of pH effect of excess reagent stability of the complexes and the tolerance limit for many metal ions and common anions have been reported The two methods have been applied to the determination of uranium in eygeptian monazite sand Spectroscopy Letters Volume 25 Issue 4 June 1992 pages 585 - 592http://blogs.najah.edu/staff/nidalzatar/article/Spectrophotemetric-determination-of-cobalt-in-aqueous-solution-using-di-2-pyridyl-ketone-derivatives-Published ArticlesA method for the spectrophotometric determination of cobaltII is presented with a comparison of the binary complexes formed by cobaltII with di-2-pyridyl ketone nicotinoylhydrazone DPKNH di-2-pyridyl ketone 2-thiophenoylhydrazone DPKTH and di-2-pyridyl ketone benzoylhydrazone DPKBH in 50 vv ethanolic solution CobaltII forms 1:2 complexes with the three reagents Maximum absorbance is at 372 nm for CoII-DPKNH at 389 nm for CoII-DPKTH and at 370 nm for CoII-DPKBH Ranges of linearity effects of pH and excess reagent sensitivity stability of the complexes and tolerance limits of ions are reported It was concluded that the system with DPKTH is the best followed by DPKNH and then DPKBH The method was applied to the determination of cobalt in different alloys Analytica Chimica Acta Volume 259 Issue 1 5 April 1992 Pages 175-179 http://blogs.najah.edu/staff/nidalzatar/article/Spectrophotometric-Determination-of-Cobalt-with-Di-2-Pyridyl-Ketone-BenzoylhydrazonePublished ArticlesA method for the spectrophotometric determination of cobalt II by complexation with di-2-pyridyl ketone benzoylhydrazone DPKBH in 50 vv ethanolic solution is described Cobalt II forms a 1:2 complex with DPKBH The complex has maximum absorbance at 370 nm Beers law is obeyed over the range 01 - 28 gml-1 The effect of pH effect of excess reagent stability of the complex and the tolerance limit of many metal ions have been reported The method is applied to the determination of cobalt in different alloys containing other metals ions Spectroscopy Letters Volume 24 Issue 9 November 1991 pages 1145 - 1152http://blogs.najah.edu/staff/nidalzatar/article/Simultaneous-Spectrophotometric-Determination-of-IronII-and-IronIII-in-Mixtures-Using-Di-2-pyridyl-Ketone-BenzoylhydrazonePublished ArticlesA method for simultaneous spectrophotometric determination of total iron ironII and ironIII in mixtures containing other metal ions has been described The method is based on the complexation of iron with di-2-pyridyl ketone benzoylhydrazone DPKBH in 50 vv ethanolic solution IronII complex with DPKBH exhibits two absorption maxima at 360 and 650 nm meanwhile ironII1 complex with DPKBH exhibits only one maximum at 360nm IronII and ironIII complexes with DPKBH have similar behaviour at 360nm Iron forms 1:2 complexes with the reagent Beers laws are obeyed over the ranges 01-2 gml-1 and 04-5 grn1-l for ironII complexes at 360 and 650nm respectively IronIII showed results similar to those obtained for ironII at 360nm The effect of pH effect of excess reagent the stability of complexes and the tolerance limit of many metal ions have been reported The method is applied to the determination of total iron ironI1 and ironII1 in synthetic solutions Spectroscopy Letters Volume 22 Issue 9 November 1989 pages 1203 - 1214http://blogs.najah.edu/staff/nidalzatar/article/Some-Arylidene-2-Pyridylhydrazone-Derivatives-as-Reagents-for-Spectrophotometric-Determination-of-Palladium-IIPublished ArticlesANALYTICAL LETTERS Volume: 19 Issue: 19-20 Pages: 1881-1891 Published: 1986http://blogs.najah.edu/staff/nidalzatar/article/Spectrofluorimetric-Determination-of-Terbium-as-its-Ternary-Complex-with-Edta-and-Tiron---Compositional-Studies-Optimization-of-Fluorescence-Output-and-Conversion-to-a-Flow-SystemPublished ArticlesANALYTICA CHIMICA ACTA Volume: 162 Issue: AUG Pages: 305-313 Published: 1984http://blogs.najah.edu/staff/nidalzatar/article/Automatic-spectrophotometric-method-for-the-determination-of-europium-in-mixtures-with-yttrium-and-other-lanthanidesPublished ArticlesAn automatic spectrophotometric method for the determination of europium in the presence of yttrium and other lanthanides is described The method is based on a modification of a recently devised manual procedure consisting of the reduction on a Jones reductor of europiumIII to europiumII which is used to reduce molybdophosphate to a molybdenum blue The method is capable of analysing solutions containing 10400 g of europium per ml at a rate of 20 samples per hour There is no interference from yttrium or other lanthanides and the method is suitable for application to europium determination after a group separation When applied to mineral samples coefficients of variation between 25 and 38 were obtained