Din Mohammad

URANIUM(VI) TRANSPORT THROUGH TRI-n-BUTYLPHOSPHATE KEROSENE OIL LIQUID MEMBRANE SUPPORTED IN POLYPROPYLENE FILM

Transport of uranyl ions through liquid membranes consisting of tri-n-butylphosphate (TBP) in kerosene oil supported in Celgard 2400 polypropylene microporous film has been studied. Various parameters, such as the effect of nitric acid concentration in the feed solution, TBP concentration in the organic membrane phase, stripping agent concentration and temperature on the flux of uranium across the liquid membrane, have been investigated. The results obtained have been used to elucidate the mechanism of uranium transport and stoichiometry of the diffusing species.

Age and sex dependence of selected trace metals in scalp hair of urban population of Pakistan

Concentrations of ten metals (Ag, Al, Cd, Cr, Cu, Fe, Mn, Sr, Ca and Mg) in scalp hair of urban donors from the city of Lahore, Pakistan were determined by the nitric acid/perchloric acid digestion based method by ICP-AES. The age and sex dependence of metal levels was investigated for the age groups 10-47 and 7-55 years, for females and males, respectively. In total 45 female and 42 male samples were analysed in triplicate. The maximum concentration in the male group was that of Fe, between 45 and 330 mg/kg, followed by Sr between 4.5 and 109 mg/kg. On average, the following order of metal concentration in male hair was observed: Ca > Mg > Fe > Sr > Al > Cu > Mn > Cr > Ag > Cd. For female samples Cu was found to have a maximum concentration (210 mg/kg) followed by Fe (170 mg/kg) and Sr (140 mg/kg). In this group the concentration order was: Ca > Mg > Cu > Fe > Sr > Al > Mn > Ag/Cr > Cd. A metal to metal correlation study showed that different metals were mutually correlated in male and female hair. Regression equations illustrated a distinct dependence of metal concentrations on the age of donors. The data are compared with corresponding data reported in the literature.

POTENTIOMETRIC DETERMINATION OF FREE ACIDITY AND URANIUM IN URANYL NITRATE SOLUTIONS

Free acid and uranium in uranyl nitrate solutions have been determined potentiometrically using Na2SO4−NaOH, Na2SO4−Na2CO3 and (NH4)2SO4−NaOH complexant-titrant combinations. The overall recovery of nitric acid varies in the range of 95.25 to 118.5%, depending upon the acid as well as the total uranium present, while that of uranium always a positive bias ranging from 100.2 to 106.4%. The results have been discussed in light of recent available data. It has been concluded that all the complexant-titrant combinations studied provide similar results.

Comparison of trace metal levels in the hair of Pakistani Urban and rural adult male populations

Human scalp hair samples obtained from the urban and rural adult male populations in Pakistan were investigated for six essential elements (Ca, Fe, Mg, Cu, Cr, Mn), three toxic metals (Cd, Pb, Ni), and for Al and Sr. The maximum concentration in both segments of population was that of Ca 1880–4680 ug/g for the urban; 2357–4691 μg/g for rural population. On the average the following order of metal concentrations in urban hair was observed: Ca > Mg > Fe > Al > Sr > Pb > Cu > Ni > Mn > Cr > Cd. For the rural population Cd showed the minimum concentration level (0.17–1.9 μg/g). In this group the concentration order was: Ca > Mg > Fe > Al > Pb > Sr > Mn > Cu > Ni > Cr > Cd. Metal‐to‐metal correlation study between two groups showed that different metals were weakly correlated in rural and urban hair. Regression equations indicated a distinct dependence of metal concentrations on the habitats of donors. The data were compared with corresponding data reported in literature.

Uranyi ion transport through tri-n-octylamine-xylene based supported liquid membranes

Tri-n-octylamine (TOA) dissolved in xylene has been used as carrier, constituting liquid membrane supported in Celgard 2400 polypropylene microporous film for the transport of uranyl ions against their concentration gradient from aqueous acid solutions to an alkaline aqueous phase. Effect of sttrring rate, nitric acid concentration and TOA concentration in the organic membrane phase, on the flux of uranyl ions through the membrane has been studied. Viscosity and density data have been obtained to estimate diffusion coefficients and hence the permeability coefficients to compare the same with experimental values, using distribution coefficient data, measured from solvent extraction experiments and available in the literature. Analysis of the flux data has been performed to study the stoichiometry of the chemical reaction involved in complex formation reaction. The results have been compared with simple liquid-liquid extraction data.

Nutritional and radiological impact of dietary potassium on the Pakistani population.

The nutritional status of dietary potassium and the radiological impact of its isotope (40)K were estimated for the Pakistani population. Potassium concentration was determined in dietary samples by atomic absorption spectrometry. An average potassium concentration was 4.54+/-0.89 mg/g, which leads to potassium dietary intake of 2.69+/-0.54 g/day and the radiological hazard due to (40)K activity was 79.94 Bq/day. The annual and lifetime effective doses calculated for the reference Pakistani man weighing 64 kg due to measured activity of (40)K were found to be 1.65 x 10(-4) Sv y(-1) and 8.27 x 10(-3) Sv, respectively. Measured data showed that the potassium concentration in the Pakistani diet is adequate and safe according to international standards.

Study of Matrix Effects on Determination of Trace Elements in Aluminum, Using Inductively Coupled Plasma Atomic Emission Spectrometry, 1) Selection of Spectral Lines.

The effect of an aluminum matrix on the determination of B, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Si and Zn was studied. These elements are expected to be present in high purity Al base materials. 45 spectral lines of these elements were scanned in a spectral window of 60 pm. Background equivalent concentrations were calculated and compared with existing data. Interference free spectral lines, one for each element, have been recommended to be used for analysis. Depression effects due to the Al matrix were calculated at the selected lines.

Assessment of daily iron intake for the Pakistani population

Purpose – Iron deficiency is the number one nutritional disorder in the world and is quite common in Pakistan. Iron deficiency anaemia may result from a low dietary intake, inadequate intestinal absorption, excessive blood loss, and/or increased needs. While iron overload is also responsible of number of diseases. The normal iron status of our body is usually maintained by controlling amount of iron absorbed from food. The recommended daily allowance (RDA) for adult male and female in the age from 19 to 50 years is 8 and 18mg, respectively. While RDA above 50 years is it for both genders i.e. 8mg (NIH, 2002). Nutritional status of dietary iron was estimated to combat the iron related diseases in Pakistani population.Design/methodology/approach – Food samples were collected from major cities/districts of the country using market basket method. Daily diets were prepared and analyzed for iron contents using Atomic Absorption Spectrometry (AAS).Findings – An average value of iron concentration was measured to...

Comparison of the thermal degradations of barium and lead polymethacrylates

Abstract A comparison of the thermal degradations of barium and lead polymethacrylates has been made using thermal volatilization analysis, thermogravimetry and mass spectrometry. Mechanisms of thermal degradation have been suggested.

Thermal degradation of gamma irradiated cobalt, nickel and copper polymethacrylates

Cobalt, nickel and copper polymethacrylates, which have possible applications as radiation shields, were studied for their radiation resistance. The samples were irradiated with 200 kGy to 600 kGy in an oxygen free atmosphere. The changes in degradation pattern, studied by employing various thermoanalytical techniques, are reported and discussed.