As street dust are environmentally important materials for the investigation of trace metal pollutions, the levels of heavy metal ions of street dusts from Kayseri-Turkey were determined by flame atomic absorption spectrometry (FAAS) after digestion with aqua regia. Copper, cadmium, chromium, nickel, lead, manganese, and cobalt levels in the dust samples were found in the range of 12-315, 1-45, 31-96 23-85, 49-381, 84-532, and 11-137 mug/g, respectively. The highest metal concentrations were found in the streets with heavy traffic. A good correlation was found between the metal concentrations.
The flow injection method, involving spectrophotometric detection, is proposed for the determination of perazine. The procedure is based on the oxidation of perazine by cerium(IV) sulphate(VI). Concentrations with perazine in the range 120-300 ppm have been determined with the relative standard deviation of 1.0%. The presented method was applied to the determination of perazine in pharmaceutical formulations.
The concentrations of heavy metals in the street dust Samples collected from Tokat, Turkey have been determined using flame atomic absorption spectrometry after wet and microwave digestion. Good accuracy was assured by the analysis of standard reference material. Recoveries were nearly quantitative for all elements studied (greater than or equal to 95%). The mean concentration levels of Pb, Ni, Cd, Zn, Mn, Cu, Co, and Cr were found to be 149, 65, 3.0, 63, 285, 29, 20, and 30 mug/g, respectively. The concentrations of heavy metals in the samples vary depending on the traffic density.
Two multidisciplinary field surveys, one in winter and the other in summer, have monitored the indoor microclimate, the air pollution, the deposition and origin of the suspended particulate matter and the microorganisms of the Kunsthistorisches Museum, Vienna. These surveys were part of a European project aimed at identifying potential environmental risks for conservation in museums. Experimental methodologies were refined within this study. The project underscores pros and cons of the heating ventilating and air conditioning system, proposing a more effective filtration, since the system seemed to worsen indoor pollution. The impact of mass tourism during a special exhibition was investigated, showing that even a good ventilation is unable to deal with the heat and moisture released by huge crowds. The sources of gaseous and particulate pollution were discussed. Microbiological investigations identified a considerable load of bacteria. The cleaning of paintings by brush is-shown to resuspend a considerable amount of particles, which are free to deposit again on the paintings.
A rapid, selective, and accurate method, based on derivative spectra is proposed for the quantification of thioridazine hydrochloride in the presence of its main degradation product-thioridazine sulphoxide, and vice versa. The determination of thioridazine hydrochloride was made using the second order of derivative (Deltalambda, = 22 nm, third polynomial degree) at 280 nm, while the determination of its sulphoxide is possible by applying the first order derivative spectra (Deltalambda = 22 nm, second polynomial degree) based on measurements of derivative height at 312 nm. The calibration graphs were linear up to 30 and 50 mug/mL for thioridazine and its sulphoxide, respectively. The limits of detection were 2.91 and 0.77 mug/mL. The elaborated method was applied successfully for determination of the photostability of thioridazine hydrochloride in aqueous solution and in solid phase.
Sudan Red B, an azo dye, was used as a reagent for the complexation of Ni and Co ions. The studies were carried out spectrophotometrically. The absorption spectra were monitored and the conditions were optimized in terms of dye and metal concentration, pH, and cationic and anionic effects. The log (stability constants) of the metal-dye complex were calculated using Job's method and these were of the order of 5.5 and 5.6 for Co2+ and Ni2+ complex respectively.
Abstract The purpose of this study was to determine the effect of pregnancy on serum concentrations of estradiol, progesterone and prolactin in Long-Evans rats. Female Long-Evans rats, both pregnant and non-pregnant, were used. Four groups (n = 10 rats in each group) were studied: Non-pregnant rats; pregnant rats at 7, 14, and 20 gestational days. Maternal blood was collected transcardially, and serum estradiol, progesterone, and prolactin were measured by radioimmunoassay. Commercial kits from Diagnostic Products Corporation for estradiol and progesterone, and an established in-house double antibody assay for prolactin, were utilized. Statistical analysis was performed using ANOVA, followed by Newman-Keuls post hoc test when applicable. Estradiol concentrations were increased throughout gestation from 16.2 ± 6.2 pg/mL (mean ± SD) in the non-pregnant rat to 23.2 ± 8.8, 25.0 ± 7.7, and 30.3 ± 29.6 pg/mL on gestational days 7, 14, and 20, respectively. Progesterone showed the same trend, increasing from 7.2 ± 3.6 ng/mL in the non-pregnant rats to 25.9 ± 4.8, 43.0 ± 8.6, and 47.3 ± 8.8 ng/mL on gestational days 7, 14, and 20, respectively (p<0.05). Prolactin levels were decreased from the non-pregnant state (39.2 ± 22.8 ng/mL) through the early and mid-pregnancy (25.2 ± 20.4, 16.5 ± 16.9 ng/mL, respectively; p<0.05) and rose to pre-pregnancy levels on pregnancy day 20 (39.2 ± 20.4 ng/mL). The effect of pregnancy on serum hormone concentrations in Long-Evans rats were determined and compared to non-pregnant controls. This data may assist in simulating various stages of pregnancy for use in hormonal and receptor binding studies, and in isolating pregnancy hormone effects on the central nervous system in the Long-Evans rat.
The combined negative bias in gamina-spectrometry due to pile-up and (residual) dead time losses in case of short-lived radionuclides can be corrected for by way of dead time readings. The combined loss-factor depends on the ratio of the time-constants in amplifier and ADC, and on the average decay-constant over the total spectrum during measurement. Both parameters can be determined once and for all for a given routine application. The procedure is applicable up to total dead time fractions of at least 0.3 and thus covers routine instrumental neutron activation analysis (INAA) practice with short-lived radionuclides.
A comparative, investigation of the same specimen of scleractinian Fungia fungites L. coral skeleton performed by means of both X- and gamma-ray computer axial tomography has revealed several features such as annual growth rings, gastro-vascular cavity or sclerosepta to sixths order and more. The apparent thickens of scleorosepta varied between 0.1 and 0.19 mm while the number of growth rings allows us to estimate the average annual growth ratio to about 8 mm/y. Although X-ray computer axial tomography images appear to be of a:better quality, no significant differences concerning sensitivity or spatial resolution could be noticed between the two categories of tomographs.
An intercomparison concerning the concentrations of 23 major and trace elements in recent lacustrine sediments, as determined by Instrumental Neutron Activation Analysis, has been performed by using epithermal neutrons at the Joint institute of Nuclear Research, Dubna, (Russia) and thermal neutrons at the National Institute for Physics and Nuclear Engineering, Bucharest, (Romania). Sc, La, Tb, Yb, Th, Na, Rb, Cs, Ba, As, Sb, Hf, Cr, Fe, Co, and Zn concentrations agreed within one standard deviation, Ce, Sm, Lu, Ca, Br, and Ta concentrations agreed within two standard deviation. The results were interpreted in the framework of the Upper Continental Crust model. The Factor Analysis has shown that all elements form a single cluster, irrespective of the laboratory where the analysis was performed.
The suitability of combining Instrumental Neutron Activation Analysis (INAA) and Electron Probe X-ray Microanalysis (SEM-EDX) for the classification of archaeological pottery based on their composition is illustrated with two examples of different nature and complexity: the study of Cuban aborigine pottery production and distribution and the classification of Majolica from the colonial period. The different scope and features of both techniques complement each other in achieving a more consistent and complete characterization of the composition and structure of the ceramic paste.
Radioisotope X-ray fluorescence spectrometry has been applied for multielemental analysis of bentonite clay in Syria (Aleppo belouneh). Samples were taken at different, times directly from different stores at the market, and then irradiated, after preparation, with a Cd-109 isotope source. The following elements: Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Rb, Sr, Y, Zr, Nb, and Pb were determined. The health implications of some elements are discussed, since some pregnant women in Syria consume the substance in the first semester of pregnancy, during the morning sickness (craving). Some elements seem to pose health hazard such as Pb and Fe, which are present in the range of (DL > to about 23.1 mug/g) and (4.06 to 5.2%) respectively.
Surface silica was modified with 3-aminopropyltriethoxysilane [(C2H5O)(3)-Si(CH2)(3)NH2] to get amino-modified silica. Surface characteristics and surface area of the silica-gel before and after chemical modification were determined by elemental and surface area analysis. Silica-gel modified with 3-aminopropyltriethoxysilane has been developed for the preconcentration of cobalt and nickel prior to their determination by graphite furnace atomic absorption spectrometry. Batch and column methods were used for the separation and concentration of cobalt and nickel. The experimental parameters, such as the effect of pH of the sample, shaking time in batch technique, flow rate of the eluent and the amount of silica, on retention and elution have been investigated. Cobalt and nickel were successfully recovered from brine (up to 1% NaCl) and sea-water samples.
In this study, the preconcentration of Pb2+ using a conical minicolumn packed with activated carbon (AC) was studied for preconcentration of Pb2+. The experiments showed that Pb2+ reacts with 8-hydroxyquinoline to form a complex at pH 10.0 and can be retained "on-line" on a conical minicolumn packed with activated carbon, then eluted with 20% (v/y) nitric acid. The conditions for the quantitative and reproducible preconcentration and subsequent ICP-OES determination with ultra,sonic nebulization system (USN) were studied. A total enhancement factor (N) of 500 was obtained with respect to ICP-OES using pneumatic nebulization (10 for USN and 50 for enrichment factor) for a sample volume of 25 mL. The detection limit (DL) was 0.04 mug L-1. The relative standard deviation (RSD) were 3.0%. The optimized procedure was successfully applied to the determination of trace levels of P+2 in bee honey samples.
Instrumental neutron activation analysis technique with thermal and epithermal neutrons from a 30 kW research reactor has been used to determine the concentration of some essential elements in market infant foods. The elements Ca, Cl, Fe, Mn, Mg, K, Na, V, Zn, Br, and I were found in various proportions in four infant foods widely sold in Nigeria. A comparison of the measured results and producer's quoted values indicates that the adopted experimental procedure can be used routinely for control and monitoring purposes.
One hundred sixty three ceramic fragment samples from three archaeological sites were analyzed using instrumental neutron activation analysis (INAA) to determine the concentration of 24 chemical elements: As, Ba, Cc, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, Yb, and Zn. Bivariate plots and a multivariate statistical method, discriminant analysis, were performed on the data set. Discriminant analysis identified three compositional grouping and derived two discriminant functions that account for 100% of the variance between groups. The results show, at a confidence level of 98%, that ceramics of each separate site are statistically similar among them and it can be said that a common source of raw material was used independently in each of these sites.
The distribution of natural K-40, Ra-226 and Ra-228 and artificial Cs-137 has been investigated in nonvascular mosses (9 species) and lichens (10 species) and vascular gymnosperm (1 species), angiosperm trees and shrubs (3 species) over the Kozani-Ptolemaida-Amynteon lignite basin in West Macedonia, Greece. Four lignite power plants producing about 70% of the electric energy of the country are to be found in this region. Both specific activity and transfer factors of these radionuclides have been determined by means of experiments. This study indicates that with regard to Ra-226 and Cs-137, nonvascular lichens and mosses have a much higher transfer factor (2.27 for Ra-226 and 43.77 Cs-137) compared with vascular plants (0.17 for Ra-226 and 0.03 Cs-137), but a lower one for natural K-40 (0.493 for lichens and mosses and respectively 1.190 for vascular plants).
Computer Axial Tomography (CAT) maps the distribution of the linear attenuation coefficient (LAC) over a section or over an entire object. LAC represents the product between density and mass attenuation coefficient (MAC). These parameters are influenced in complete different manners by porosity provided that pore sizes are much smaller than voxels: density lineally decreases with porosity while MAC is almost independent of it. Consequently, ill the case of single energy tomography, CAT images will be strongly influenced by the porosity. In the case of dual-energy tomography, when it results for the same section two CAT images, one depicting density and the other one the effective atomic number distributions, only the first one will reflect the sample porosity while the second one remains independent of the specimen porosity. This fact could be very useful in investigating complex samples such as rocks or soils.
Menkes disease is a lethal genetic disorder of copper transport in humans. Its current treatment is the administration of copper-L-histidine complex. However, this therapy is only effective in some cases and when started early in life. In order to develop an improved treatment, copper(II) mixed ligand amino acid complexes were studied because these complexes play an important role in the physiological copper pathway. A promising strategy is the administration of L-histidine-copper(II)-L-glutamine complex, which has been reported to be the predominant low molecular-weight copper(II) complex in human blood serum. Before the biopharmaceutical studies of L-histidine-copper(II)-L-glutamine complex, a physicochemical study of this ternary system must be performed.
A method for the determination of the riboflavin (Vitamin B,) and L-ascorbic acid (Vitamin C) in pharmaceutical preparations by voltammetry is described. The electrochemical behaviour of riboflavin and L-ascorbic acid in KH2PO4/Na2HPO4 buffer (pH = 6.8) was investigated using glassy carbon electrode. All anodic scan gave peaks at -0.47 V and +0.35 V vs. SCE for riboflavin and L-ascorbic acid, respectively. The oxidation peaks Currents are linearly dependent on the concentration of vitamins. Both vitamins can be simultaneously determined from the same voltamogram. RF can be determined in the concentration range 1.5 x 10(-6)-3 x 10(-5) M, however L-ascorbic acid in the concentration range 1.5 x 10(-4)-3 x 10(-3) M. The method proposed for the determination of riboflavin and L-ascorbic acid in multivitamin tablets is very simple, rapid and does not involve time-consuming separation steps.
