VOLUME 22, NO2, JUN 2000

Spectroscopic studies and effect of heat treatment on electrical conductivity of new diamino-dicyano thiophene complexes

The preparation and characterization of the 2,4-diamino- 3,5-dicyanothiophene complexes with Mn2+,Co2+, Ni2+, Cu2+, Zn2+, Pb2+ and UO22+ acetates have been reported The proposed structure wee round to be 1:2 (LM2) adducts of the ligand to the metal ion respectively which is supported by elemental analysis and magnetic meawaaents. Additionally mid-infrared end electronic absorption apectroscopic techniques, DTA X-ray diffraction patterns have been reported. Moreover, the electrical conductivity of some selected complexes were measured before and after beet treatment above the transition temperatures.read more

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M A EL NAWAWY ,S H B EL FETOH ,T A MOHAMED ,S R SELIM ,

Quality characteristics of potable water of Mardan city (Pakistan) and surrounding areas

Quality characteristics of 31 potable water samples collected from 18 tube wells and 13 bore wells of Mardan city and adjoining areas were chemically investigated and compared with international standards. Most of the water samples were not M for drinking due td the presence of higher oxygen demanding wastes and the possibility of biological activities. COD values in all samples were found to be above the permissible level of 4 mg O-2/l. Tube well waters were however, less polluted compared to bore well waters due to lower nitrite level. Calcium concentration in tube well and in bore well waters is below the permissible level except at Khat Koruna (350.96 mg/l). Magnesium concentration in both tube well and bore well waters is above the threshold limit of 150 mg/l except at Muqam Mandi and Shamsul Qamar Bagh. Results suggest that magnesium concentration compared to calcium in almost all samples were high. Results also show that a few samples were not potable because of the synergistic effect of magnesium and sulphate which imparts a laxative nature. Other parameters including Na+ and K+ were found well within the limits.read more

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M RIAZ ,M KHAN ,I U HAQ ,A R KHAN ,M AKIF ,W A KHAN ,

Determination of iron and manganese in tea samples by flame atomic absorption spectroscopy

Tea samples, marketed by different companies through out the country, have been collected end analyzed for inn end manganese by flame atomic absorption spsectroscopy. Dry ashing well as wet procedures were employed for decomposing the tea samples and results obtained san both the procedures were compared The average amount of iron, estimated in thirty samples, war 9.38 ppm while that of managanese was found 175 ppm. For both metals relatively higher results were obtained when samples wan decomposed with sulphuric acid and hydrogen peroxide.read more

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R ALEEM ,F YASMEEN ,J ANWAR ,

Microdetermination of sulphate by indirect spectrophotometry

An indirect spectrophotometric method is developed for sulphate determination The method is based on the reduction of sulphate to sulphide by fusing the sulphate sample with metallic sodium in solid date. The hued contents were dissolved in water and fibered An aliquot of the filtrate was reacted with iron(III)phenanthroline solution to reduce irm(III) to iron(II) which formed a red colour complex with 1,10-phenanthroline. Absorbance of the final solution was measured at 515 am and plotted against sulphate concentration. The method proved itself sufficiently accurate and precise and equally good for soluble and insoluble sulphates as well as for sulphate content in solid and Liquid samples. The values of standard deviation and relative standard deviation calculated from absorbance values often solid samples of sodium sulphate were 0.006 and 0.82 % respectively. Effect of concerned parameters was checked and the developed method was applied for sulphate determination in a number of real samples.read more

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J ANWAR ,WAHEED UZ ZAMAN ,F YASMIN ,

Evaluation and transport of nitrogen and phorphorus by river Indus at Kotri barrage

Water samples at Kotri barrage were collected during Jan 1994 to Dec. 1995 and analyzed for nitrite, nitrate, ammonia, organic nitrogen, orthophosphate and condensed phosphate. The concentrations were multiplied with water discharges to obtain load of each ion including total nitrogen and phosphorus in the river Indus. The transport of nitrogen and phosphorus to Arabian sea and to irrigation channels at Kotri barrage were calculated. The variation in their phosphate phosphorus were dominant and contributed 64% and 73% of total nitrogen and phosphorus transported.read more

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M Y KHUHAWAR ,I A ANSARI ,V K DEWANI ,

Spectrophotometric determination of some indole drugs

A spectrophotometric method has been developed for the quantitative determination of indole drugs, i.e., yohimbine, reserpine and rescinnamine on complexation with iodine. The coloured complexes exhibit absorption maxima in the region 360-369 nm. The RSD( Relative Standard Deviation) of the method is 2.0%. The method is simple, rapid and convenient for routine analysis of the drugs.read more

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I HUSSAIN ,I AZHAR ,A Q N MANZAR ,

Determination of urinary putrescine and cadaverine of cancer patients by gas chromatography

Capillary gas chromatography (GC) was examined from the determination of urinary putrescine(Pu) and cadaverine (CA) based on off line precolumn derivatization with trifluoroacetylacetone (FAA), GC was carried out on BP5 (25m x 0.22 mm id) column with a layer thickness of 0.25 mum at 230 degreesC with a heating rate of 2 degreesC/min upto 250 degreesC, a nitrogen flow rate of 3.5 ml/min, a split ratio of 1:15 and detection by FID. The method was used for determinastion of Pu and CA in urine of cancer patients before and after radiotherapy and healthy volunteers. The amount found was in the range of 0.04-3.89 mug/ml with a coefficient of variation (C.V) of 1.25-5.56%.read more

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M Y KHUHAWAR ,A A MEMON ,M I BHANGER ,

Heavy trace metal and macronutrient levels in various soft drinks and juices

The levels of selected heavy toxic trace metals (Cr, Ni, As, Fe, MR Cd, Cu, Hg, Pb, and Zn) and macro-nutrients (Na, K, Mg and Ca), along with relevant pH and TDS (total dissolved solids) measurements on local/imported carbonated waters, juices mineral spring and natural waters are reported. The atomic absorption technique was applied for these estimations conducted on thirty four samples procured from local markets. The study revealed that nutritional quality of local carbonated waters was better than that of fruit juices, both in terms Of heavy toxic true metals and macro-nutrient levels. The local Pepsi cola sample contained maximum mercury (0.535 mg/L) while Tops showed maximum arsenic (0.837 mg/L). Out of cardioard packed juices. apple juice was found to have maximum arsenic (2.920 mg/L). Local fruit juices were found not to conform with the standards allowed for safe ingestion of micro- and mure-metals in various drinks, as laid down by WHO.read more

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K MASUD ,W ASHRAF ,M JAFFAR ,

Reaction of fulgides: Regioselectivety in the ring opening reactions of unsymmetrical bis-substituted dimethylene-succinic anhydrides with nucleophiles

Nucleophiles were added regioaelectivcty on the carbonyl group in conjugation with the diphenyl methylene group of fulgide 1, however in the heterocyclic fulgides such as lad 10a the addition takes place on the carbonyl group not in conjugation with the heterocycle ring. The addition of dicyanomethyl anion to heterocyclic fulgides resulted in novel photochromic derivatives 12a having an absorption maxima for the coloured forms above 620 nm.read more

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A M ASIRI ,

Mass spectral studies of 6,8-disubstituted-3-(3 ',5 '-disubstituted 3 ',4 '-disubstituted phenylmethyl-, ethenyl)isocoumarins

Mass spectra of 6,8-dihydroxy-3-(3 ' ,5 ' -dihydroxyphenylmethyl-, 3 ' ,4 ' -dihydroxyphenylethenyl) isocoumarins ( 2b & 3b) and their methylether derivatives (2a & 3a) are discussed. The mass fragmentation patterns wen derived with the help of LREIMS, HREIMS. and link scan measurements.read more

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N H RAMA ,K ZAMANI ,A SAEED ,M T HUSSIAN ,R IQBAL ,