Stannous Chloride Solution Research Articles

Assessment of the effect of Bacopa monnieri (L.) Wettst. extract on the labeling of blood elements with technetium-99m and on the morphology of red blood cells

Bacopa monnieri (L.) Wettst. (BM), a traditional Ayurvedic medicine, used for centuries as a memory enhancing, anti-inflammatory, antipyretic, sedative and antiepileptic agent. BM extract have been extensively investigated by several authors for their neuropharmacological effects. In nuclear medicine, red blood cells (RBC) labeled with technetium-99m (99mTc) have several clinical applications. However, data have demonstrated that synthetic or natural drugs could modify the labeling of RBC with 99mTc. As Bacopa monnieri is extensively used in medicine, we evaluated its influence on the labeling of RBC and plasma proteins using technetium-99m (99mTc). This labeling procedure depends on a reducing agent and usually stannous chloride is used. Blood was incubated with BM extracts. Stannous chloride solution and 99mTc were added. Blood was centrifuged and plasma (P) and blood cells (BC) were isolated. Samples of P or BC were also precipitated, centrifuged and insoluble fraction (IF) and soluble fraction (SF) were separated. The percentage of radioactivity (%ATI) in BC, IF-BC and IF-P were calculated. The %ATI significantly decreased on BC from 95.53±0.45 to 35.41±0.44, on IF-P from 80.20±1.16 to 7.40±0.69 and on IF-BC from 73.31±1.76 to 21.26±1.40. The morphology study of RBC revealed important morphological alterations due to treatment with BM extracts. We suggest that the BM extract effect could be explained by an inhibition of the stannous and pertechnetate ions or oxidation of the stannous ion or by damages induced in the plasma membrane.

Some Experimental and Theoretical Investigations on Fire Retardant Coir/Epoxy Micro-Composites

This article reports some experimental and theoretical investigations on fire retardant coir/epoxy micro-composites. The coir fiber is treated with saturated bromine water for increasing the electrical properties and then mixed with stannous chloride solution for improving the fire retardant properties. Only 5% (approximately) of fire retardant filler reduces the smoke density by 25% and the LOI value increases to 24%. The mechanical properties of the coir/epoxy micro-composites are not affected much after incorporation of filler. Flexural strength and flexural modulus of the NET increases tremendously compared to NEU and NE. Multiquadric radial basis function (MQRBF) method is applied for static and dynamic analysis of coir/epoxy micro-composite plate under uniformly distributed load. Damping behavior and natural frequencies are observed in NE, NEU, and NET. MQRBF is applied for spatial discretization and Newmark implicit scheme is used for temporal discretization. The discretization of the differential equations generates greater number of algebraic equations than the unknown coefficients. The multiple linear regression analysis, which is based on the least square error norm, is employed to obtain the coefficients. Simple supported and clamped boundary conditions are considered for verification of present results and they are compared with other existing analytical methods.

Application of Microcontact Printing to Electroless Plating for the Fabrication of Microscale Silver Patterns on Glass

Microcontact printing (microCP) and electroless plating are combined to produce microscale patterns of silver on glass substrates. Silver patterns with feature sizes of 0.6-10 microm stripes are fabricated using two methods. (1) The printing seeding layer (PSL) method is to apply microCP to directly print the catalyst Sn pattern for further electroless plating. (2) The printing masking layer (PML) method is to use microCP to print the octadecyltrichlorosilane (OTS) self-assembled monolayer as a masking layer on glass substrates, which then become Sn-activated in the unstamped regions by immersing the substrates in stannous chloride solution. After the electroless silver plating, the PML method has a better selectivity of silver deposition than the PSL method. In addition, variation of the deposited silver thickness as a function of the plating time and temperature is discussed.

Assessment of the effect of Fucus vesiculosus extract on the labeling of blood constituents with technetium-99m and the histological modifications on the shape of the red blood cells

Natural products are widely used as food or food additives or medicines for humans. We are trying to develop a model to assess the possible toxic properties of natural products, such as Fucus vesiculosus, utilized in popular medicine. Red blood cells (RBC) labeled with technetium-99m (99mTc) are used in various procedures in nuclear medicine. This labeling procedure depends on a reducing agent, and stannous chloride is used. There is evidence that this labeling may be altered by drugs. We have investigated the possibility that F. vesiculosus extract is capable of altering the labeling of blood elements with 99mTc. Blood was incubated with F. vesiculosus extract and stannous chloride solution and Tc-99m added. Blood was centrifuged and plasma (P) and blood cells (BC) were isolated. Samples of P or BC were also precipitated, centrifuged and insoluble (IF) and soluble (SF) were separated. The percentages of radioativity (%ATI) in BC, IF-P and IF-BC were calculated. Histological preparations of the RBC treated with F. vesiculosus revealed that this extract is capable of promoting important modifications on the shape of the RBC. The%ATI decreased on BC from 93.6±2.3 to 29.0±2.7, on IF-P from 77.6±1.2 to 7.5±1.0 and on IF-BC from 80.0±3.4 to 12.6±4.8. Once the RBC labeling procedure with 99mTc depends on the presence of stannous (+2) ions, the substances present in the F. vesiculosus extract should increase the valence of these ions to stannic (+4). This would decrease the%ATI on blood elements and indicate the presence of oxidant agents in the F. vesiculosus extract.

Alternativa analítica para especiação físico-química de mercúrio em águas costeiras tropicais

The determination of the physical-chemical mercury speciation in tropical coastal waters using the derivatization technique with CVAFS detection was optimized. This methodology is able to separate the elementary, reactive, organic and total mercury phases with low operational costs. The importance of bromide chloride solution, the diluted aqua regia, used as the oxidative solution, and different compositions of the reductive solution of stannous chloride were tested and the better results for coastal waters are presented. The recuperation of the sum of the different phases ranges from 80 to 94% of the total Hg content in duplicates of different marine samples. The optimized methodology permits important studies on the mercury cycle in the coastal environment.

Sensitive determination of mercury in tap water by cloud point extraction pre-concentration and flow injection-cold vapor-inductively coupled plasma optical emission spectrometry

A pre-concentration and determination methodology for mercury at trace levels in water samples was developed. Cloud point extraction was successfully employed for the pre-concentration of mercury prior to inductively coupled plasma optical emission spectrometry coupled to a flow injection with cold vapor generation system. The mercury was extracted as mercury-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol [Hg(II)-(5-Br-PADAP)] complex, at pH 9.2 mediated by micelles of the non-ionic surfactant polyethyleneglycolmono- p-nonylphenylether (PONPE 5). Cold vapor generation was developed from 100 μl of the extracted surfactant-rich phase by means of a stannous chloride (SnCl 2) solution as reluctant. An exhaustive study of the variables affecting the cloud point extraction with PONPE 5 and cold vapor mercury generation from the surfactant phase was performed. The 50-ml sample solution pre-concentration allowed us to raise an enrichment factor of 200-fold. The lower limit of detection obtained under the optimal conditions was 4 ng l −1. The precision for 10 replicate determinations at the 0.5-μg l −1 Hg level was 3.4% relative standard deviation (R.S.D.), calculated with the peak heights. The calibration graph using the pre-concentration system for mercury was linear with a correlation coefficient of 0.9998 at levels near the detection limits up to at least 50 μg l −1. The method was successfully applied to the determination of mercury in tap water samples.

Assessment of the effect of Maytenus ilicifolia (espinheira santa) extract on the labeling of red blood cells and plasma proteins with technetium-99m

We are trying to develop a model to assess properties of products utilized in popular medicine. Maytenus ilicifolia is used in herbal medicine. Red blood cells (RBC) labeled with technetium-99m (99mTc) are employed in nuclear medicine. This labeling procedure depends on a reducing agent and stannous chloride is used. There is evidence that this labeling may be altered by drugs. We have investigated the possibility of M. ilicifolia extract being capable to alter the labeling of blood elements with 99mTc. Blood was incubated with M. ilicifolia extract. Stannous chloride solution and Tc-99m were added. Blood was centrifuged and plasma (P) and blood cells (C) were isolated. Samples of P or C were also precipitated, centrifuged and insoluble (IF) and soluble (SF) were separated. The percentages of radioactivity (%ATI) in C, IF-P and IF-C was calculated. The %ATI decreased on C from 93.6±2.3 to 29.0±2.7, on IF-P from 77.6±1.2 to 7.5±1.0 and on IF-C from 80.0±3.4 to 12.6±4.8. Once in RBC labeling procedure with 99mTc depends on the presence of stannous (+2) ions, the substances of the M. ilicifolia extract could increase the valence these ions to stannic (+4). This fact would decrease the %ATI on blood elements and indicate the presence of oxidant agents in the M. ilicifolia extract.

The effect of drugs on the labeling of blood elements with technetium-99m.

The influence of drugs on the labeling of red blood cells and plasma proteins with 99mTc has been reported. Any drug, which alters the labeling of the tracer, could be expected to modify the disposition of the radiopharmaceuticals. Red blood cells (RBC) labeled with technetium-99m (99mTc) are used for several evaluations in nuclear medicine. We have evaluated the effect of Thuya occidentalis, Peumus boldus and Nicotiana tabacum (tobacco) extracts on the labeling of RBC and plasma and cellular proteins with 99mTc. Blood was incubated with the drugs. Stannous chloride (SnCl2) solutions and 99mTc were added. Plasma (P) and blood cells (BC) were separated. The percentage of radioactivity (%ATI) bound to P and BC was determined. The %ATI on the plasma and cellular proteins was also evaluated by precipitation of P and BC samples with trichloroacetic acid (TCA) and isolation of soluble (SF) and insoluble (IF) fractions. The analysis of the results shows that there is a decrease in %ATI (from 97.64 to 75.89 percent) in BC with Thuya occidentalis extract. The labeling of RBC and plasma proteins can be decreased in presence of tobacco. This can be due either a direct or indirect effect (reactive oxygen species) of tobacco. The analysis of radioactivity in samples of P and BC isolated from samples of whole blood treated with Peumus boldus showed a rapid uptake of the radioactivity by blood cells in the presence of the Peumus boldus, whereas there was a slight decrease in the amount of 99mTc radioactivity in the TCA-insoluble fraction of plasma. This study shows that extracts of some medicinal plants can affect the radiolabeling of red blood cells with 99mTc using an in vitro technique.

Development of spray technique for the preparation of thin films and characterization of tin oxide transparent conductors

Tin oxide (TO) thin films of different thickness have been prepared by a specially designed, fabricated and developed spray technique using a stock solution of alcoholic stannous chloride (0.5 M concentration). The films have been characterized by X-ray diffraction, optical transmission and electrical studies. The XRD patterns show that the films are polycrystalline in nature and the results are in good agreement with ASTM data. From the XRD data ` d' values and grain size of the crystallites have been calculated. The grain size of TO films lie in the range 300–514 Å. Refractive index ( n) and thickness of the films have been determined using optical transmission data. The effect of film thickness on different parameters (figure of merit, conductivity, transmission and refractive index) is presented and discussed. Variation of sheet resistance as a function of film thickness has been discussed. It is observed that the optical and electrical properties of TO films strongly depend on the thickness of the film. Optimum conditions are established based on the maximum figure of merit value. The film prepared at 450°C with the maximum thickness of 5262 Å showed the maximum figure of merit 0.7 × 10 −3 Ω −1. The corresponding film properties are R = 30 Ω per square, T f = 0.70.

Technetium-99m complex of N-(2-pyridylmethyl)iminodiacetic acid as a new renal radiopharmaceutical.

A tetradentate chelating agent constituting of an iminodiacetic acid group and a nitrogen atom of pyridine, N-(2-pyridylmethyl)iminodiacetic acid (PMIDA), was coordinated with 99mTc and evaluated as a renal functional agent. The complex of PMIDA with 99mTc was prepared by using a stannous chloride solution as a reducing agent. The chelating efficiency was analyzed by thin layer chromatography and electrophoresis. Chelation with 99mTc resulted in a single radiochemical product. Biological studies were performed in mice and rats. 99mTc-PMIDA was removed from the circulation solely by the kidneys. Clearance of 99mTc-PMIDA from the blood and the kidneys was as rapid as that of 99mTc-diethylenetriaminepentaacetic acid. The rate of blood clearance was unaffected by the administration of probenecid (a test for tubular secretion by the weak-acid mechanism), so that the glomerular filtration rate could be estimated by measuring its clearance from the blood. The results in animals with myohemoglobinuric acute renal failure suggested that 99mTc-PMIDA might be a useful renal function radiopharmaceutical.

Automated determination of mercury at ultra trace level in waters by gold amalgam preconcentration and cold vapour atomic fluorescence spectrometry

Mercury in water samples is oxidized to its divalent ion form by an acid digestion procedure. The mercury is then reduced to its elemental form by a stannous chloride solution in a continuous flow system. The mercury vapour is separated and an aliquot is diverted into a gold wire absorber via a flow injection valve to form an amalgam. The mercury is then thermally desorbed and is swept with a stream of argon into a flow cell of an atomic fluorescence spectrometer where the fluorescence is measured at 253.7 nm. The operation of the analytical system is fully automated. The detection limit of the method is 2 ng l −1, and the precision is 3% R.S.D. The results for standard reference materials agree closely with the certified values.

Pb, Cd and Hg contents of bivalves collected during the different seasons of the year

Levels of lead, cadmium and mercury were determined in talaba ( Ostrea malabonensis, F.), tahong ( Perna viridis, L.), halaan ( Arca spp.) and tulya ( Corbicula manilensis, P.) including the seawater where the saltwater bivalves were harvested. The bivalves were sampled during the dry (March–June), wet (July–October) and cold (November–February) seasons of the years 1983–1985. The heavy metals were determined by atomic absorption spectroscopy. The solutions for Pb and Cd determination were prepared by dry ashing at 400°C with the use of 20% H 2SO 4 as ashing aid followed by wet oxidation of the residue with sulfuric acid and 30% H 2O 2. Samples for total mercury determination were prepared by solubilization at 50°C with concentrated H 2SO 4, oxidized with 6% KMnO 4 solution and reduced with stannous chloride solution. The average concentration of Pb, Cd and Hg in the bivalves ( talaba, tahong, halaan and tulya) ranged from 0·64 to 2·24 ppm, 0·06 to 0·66 ppm and 0·62 to 11·68 ppb, respectively. However, the variations due to sample and season of the Pb and Cd contents in the bivalves were found insignificant. In contrast, the Hg content of the bivalves varied significantly with the sample and the season. The same trends were also noted in the Pb, Cd and Hg content in the seawater which ranged from 0·66 to 1·66 ppm, 0·07 to 0·10 ppm and 1·8 to 2·6 ppb, respectively. The saltwater bivalves exhibited low bio-accumulation factors for the three metals studied. Overall, the findings demonstrated that the four bivalves are safe for human consumption and that the ecosystems where they were harvested do not pose any hazard to man or to marine life. However, caution should be taken if these bivalves are to be considered for feeding children. For example, the FAO/WHO recommendation for Pb is 5 μg/kg body weight/day for adults. However, children have about five times the gastrointestinal absorption rate of adults and consumption of these bivalves by children may predispose them to Pb exposure.

Photoelectrochemical behaviour of tin monosulphide

Polycrystalline samples of tin monosulphide were prepared by passing H 2S through an acidic solution of stannous chloride. The structure and the composition of the samples were confirmed by X-ray diffraction and energy dispersive analysis of X-rays. Hall measurements showed the samples to be n type and the mobility of the majority carriers was found to be 11.4 cm 2 V −1 s −1. Reflectance spectra of the powder samples indicated a band gap of 1.29 eV. The photoelectrochemical behaviour of n-SnS was studied in Fe 3+/Fe 2+, Ce 4+/Ce 3+ and I 2/I − redox couples. Capacitance measurements yielded a donor density equal to 1.26 × 10 16 cm −3, which is in agreement with the value 2.28 × 10 16 cm −3 obtained from Hall measurements. Cyclic voltammetric studies on platinum as well as n-SnS were carried out with the best suitable Ce 4+/Ce 3+ redox couple and the onset potential (+0.46 V vs. a saturated calomel electrode (SCE)) was found to be in good agreement with the value of the flat-band potential obtained from impedance measurements. The semiconductor was found to be stable against photocorrosion in the Ce 4+/Ce 3+ redox couple over a period of 60 h. A photoconversion efficiency of 0.63% was obtained with the cell n-SnS/Ce 4+, Ce 3+/Pt. The photoelectrochemical studies were carried out with a tungsten-halogen lamp and with solar radiation. Both illuminations gave similar results.

Microdetermination of arsenic in water, spectrophotometrically, by arsine-silver diethyldithiocarbamate-morpholine-chloroform system

An improved spectrophotometric method for microdetermination of arsenic in water using arsine-silver diethyldithiocarbamate-morpholine-chloroform system is described. Sensitivity and molar extinction coefficient are 0.0055 μg As/ml and 1.35 × 10 4 M −1 cm −1 at 510 nm. The color is stable for 3 days. Six other systems are also studied and compared including the silver diethyldithiocarbamate-pyridine system. Interference due to 19 diverse ions has been studied. Antimony interference is removed by excess stannous chloride solution. The method replaces the commonly employed less stable arsine-silver diethyldithiocarbamate-pyridine method.

119Sn Mossbauer spectroscopy of a mixed aqueous EHDP and stannous chloride solution—Evidence for a EHDP-Sn(II) complex

In this work 119Sn Mossbauer spectroscopy performed on a mixed aqueous 0.1 M EHDP and 0.01 M stannous chloride solution has shown a EHDP-Sn(II) complex.

Determination of arsenite, arsenate and monomethylarsonic acid in aqueous samples by gas chromatography of their 2,3-dimercaptopropanol (bal) complexes

Procedures are described for the determination of arsenite, arsenate and monomethylarsonic acid in aqueous samples. The arsenicals (after reduction of arsenic to the tervalent state) readily react with 2,3-dimercaptopropanol (BAL) to yield their BAL complexes. The products are extracted with benzene and introduced into a gas Chromatograph equipped with a flame-photometric detector for sulphur. One aliquot of sample is treated with stannous chloride solution and potassium iodide solution to reduce arsenate and monomethylarsonic acid, then BAL is added and the complexes are extracted with benzene. The extract is analysed for total inorganic As plus monomethylarsonic acid. Magnesia mixture and phosphate solution are added to another aliquot to remove arsenate by co-precipitation with magnesium ammonium phosphate. The precipitate is filtered off and arsenite determined in the filtrate. The detection limits are 0.02 ng of As for arsenate and arsenite and 0.04 ng of As for monomethylarsonic acid.

Pollution-free method for the determination of iron in iron ore

A method for the determination of total iron in iron ores and concentrates is described which avoids the use of mercuric chloride. The sample is decomposed either by an acid attack or by fusion with sodium peroxide. The hot sample solution in about 6 M hydrochloric acid is treated with hot 10% stannous chloride solution till pale yellow, followed by addition of a slight excess of 2% titanous chloride solution; the excess is then oxidized with perchloric acid (1 + 1). The solution is rapidly cooled in ice-water, and the iron (II) is titrated with potassium dichromate (sodium diphenylsulphonate as indicator). The results show the same degree of precision, accuracy, and degree of interference as those obtained by the standard stannous chloride—mercuric chloride method.

31p NMR spectroscopy of mixed aqueous Na pyrophosphate and stannous chloride solutions. Evidence for pyrophosphate-Sn complex formation

99mTc pyrophosphate and 99mTc organic phosphorus compounds have been widely used in recent years for bone scintigraphy. These compounds showed preferential uptake by the human skeleton which al lowed the external imaging of normal and pathological bones (1-5). The labeled pyrophosphate was usually prepared in two steps (6) at room temperature. Aqueous Na pyrophosphate solution was first m ixed with a stannous chloride solution. 99mTc eluted from a 99Mo generator was, then, added and the pharmaceutical was ready for intravenous injection. The mode of formation and the structure of the labeled pyrophosphate remained poorly understood. Three possibilities were proposed: (a) Sn(I1) ions reduce pertechnetate ions to a chemical form which allows the binding of Tc with pyrophosphate, (b) Sn(I1) ions are first bound to pyrophosphate, then, exchange with Tc in the appropriate chemical form, (c) a double Tc-Sn-pyrophosphate complex is formed. In the present work, we tried to determine the chemical reaction which occurred during the first step of the labeled compound preparation before adding pertechnetate ions. In a previous paper (7) ‘19Sn M iissbauer spectroscopy of the m ixed aqueous pyrophosphate stannous chloride solutions showed the presence of a pyrophosphate-Sn complex at 77 K. In the present work, 3’P NMR spectroscopy was used to confirm the presence of this complex at room temperature and to get information on its chemical structure. 31P Fourier transform NMR spectra were carried out with a Varian XL 100 spectrometer with an operating frequency of 40.5 MHz. D20 present as the bulk solvent provided the deuterium lock for field frequency stabilization. Data acquisition emp loyed a spectral width of 2500 Hz with 4096 accumulated data points and a pulse repetition rate of 1 Hz. The Fourier transform was carried out with a Varian 620 L 100 data processor and 4 K time doma in points providing a resolution of 1 Hz/point. Measurements were performed at 25°C on 2.0-ml samples contained in lo-mm diam sample tubes and with low-speed spinning. F ive hundred to one thousand transients were required to obtain each spectrum. Proton decoupl ing was used with a I-kHz noise bandwidth. Chemical shifts were expressed relative to an 85% H3P04 reference in D20, with shifts to higher frequency expressed as positive.

Technical problems associated with the production of technetium Tc 99m tin(II) pyrophosphate kits

The amount of tin(II) required for adequate reduction, complexation, and stability of technetium Tc 99m pertechnetate in radiopharmaceutical kits, and methods of preventing the loss of tin(II) during formulation of these lyophilized kits are investigated. Tin(II) loss from stannous chloride solutions was studied under several conditions, including room air versus nitrogen atmospheres, during vial filling in a laminar-flow hood with samples frozen on dry ice versus samples at room temperature, during lyophilization, and during storage under refrigerated, ambient, and elevated temperatures. Various amounts of stannous chloride, ranging from 5 to 1000 microgram/ml, were used in formulating sodium pertechnetate Tc 99m kits containing 100 mCi technetium Tc 99m and 0.4 microgram total technetium. Samples were removed at various times; hydrolyzed technetium, pertechnetate, and technetium Tc 99m pyrophosphate were isolated on instant thin-layer chromatography-silica gel and quantified with a scintillation counter. The time necessary to deoxygenate distilled water by nitrogen purging was measured. Several sources of stannous chloride were assayed for tin(II) content. Tin(II) loss occurs rapidly in solution (15% in one hour) unless continuously protected with nitrogen, and during vial filling in a laminar-flow hood unless frozen with dry ice. No substantial loss of tin(II) was detected during lyophilization or during storage of lyophilized product at any of the three temperatures. A minimum of 400 microgram tin(II) was required to provide 90% technetium Tc 99m pyrophosphate at six hours after preparation. Adequate deoxygenation of small quantities (450 ml) of water was accomplished in less than one hour. Some stannous chloride salts were highly oxidized in the dry state, and only high-purity elemental tin wire gave acceptable yields of tin(II).

Some aspects of the behaviour of inorganic constituents of two Australian brown coals during hydroliquefaction

An examination has been made of the changes taking place in the mineral and other inorganic matter contained in two Australian brown coals as a result of hydroliquefaction of the coal in tetralin and hydrogen at 25 MPa and 395 °C. Iron sulphides were found to be reduced to pyrrhotite, whereas iron carboxylates decomposed mainly to magnetite. Calcium carboxylates formed predominantly vaterite, whereas when coals were subjected to low-temperature ashing calcite was formed. Amorphous tin oxide, precipitated onto the coal by hydrolysis of stannous chloride solution, was largely reduced during hydrogenation to liquid tin, some of which reacted with hydrogen sulphide to form herzenbergite.