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1.
131I, 137Cs and 134Cs were observed in environmental samples in Milano (40°N), Italy and Thessaloniki (45°N), Greece, soon after the nuclear accident in Fukushima, Japan. The radionuclide concentrations were determined and studied as a function of time. In Thessaloniki the 131I in air was observed for the first time on March 24, 2011. In Milano, the first evidence of Fukushima fallout has been confirmed with 131I and 137Cs measured in wet precipitation collected 2 days later. The maximum 131I activity concentration in air of 467 ± 25 μBq m?3, observed in Milano on April 3–4, 2011, was almost similar to the highest value of 497 ± 53 μBq m?3 observed in Thessaloniki. The 134Cs/137Cs activity ratio values in air were around 1 in both regions. Soil, grass and milk samples were contaminated with 131I and 137Cs at a low level. Finally, a dose assessment for these two areas showed clearly that the detected activities in all environmental samples were far below levels of concern.  相似文献   

2.
Radionuclide calibrator used in nuclear medicine is the radiation detection equipment for measuring radiopharmaceutical activity. This instrument consists of an ionization chamber with an electrometer. This paper examines the variation in the amounts of radioactivity that is associated with dose calibration. The amount of radioactivity in each sample was measured by CMI and compared with values obtained from radionuclide calibrators over a year period. Measurements of serum bottles were within 10 % for 18F and 90Y, 10–15 % for 131I and 51Cr, 10–20 % for 99mTc, 15–20 % for 67Ga, 10–25 % for 111In, 15–30 % for 201Tl and 15–45 % for 123I.  相似文献   

3.
Lawsonia inermis (henna) is one of the most effective medicinal plants and it has been using for treatment of wounds and burns for centuries. The using of Henna leaves is very popular for cosmetic as well as medicine in many countries. Henna leaves contain lots of different compounds and lawsone (LW) is the main one. In current study, extraction with bidistillated water of henna leaves was performed and LW was isolated by using high performance liquid chromatography system. Chemical structure of LW was evaluated by nuclear magnetic resonance method. LW was radiolabeled with iodine-131 (131I) radionuclide which is well known for nuclear imaging and therapy in nuclear medicine by utilizing iodogen method. The yield of radiolabeling of LW (131I-LW) was calculated as 92.70 ± 4.312 % (n = 10) by thin layer radio chromatography. Its in vivo biological activity was investigated by biodistribution studies which were performed by using healthy female and male Balb/C mice. According to results of biodistribution, uptake of 131I labeled LW compound in uterus, breast and ovary for female mice and prostate in male mice was higher than other organs in the body.  相似文献   

4.
The seeds of winter wheat were pretreated with three different doses of low-energy N+ beams, and its seedlings were subjected to UV-B irradiation (10.08?kJ?m?2?day?1) at three-leaves stage. The growth characteristic of seeds, the oxidative damage to membrane system induced by UV-B radiation, and the alleviating effects of N+ beams pretreatment to radiation damage were investigated. The results showed that the germination rate and seedling rate, respectively, increased 14.09?±?1.03 and 13.91?±?1.21?% compared with control (CK) at the dose of 4.0?×?1016 ions/cm2. When seedlings were exposed to UV-B radiation, the pretreatment method under the dose of 4.0?×?1016 ions/cm2 made the activity of peroxidase and superoxide dismutase increasing, the content of chlorophyll enhancing, but the content of malondialdehyde reducing significantly compared with that of the single UV-B radiation. Whereas, the activity of catalase irradiated by UV-B improved notably under the pretreatment dose of 8.0?×?1016 ions/cm2. In addition, after being irradiated with UV-B, the content of soluble protein and glutathione whose seeds were pretreated by the dose of 6.0?×?1016 ions/cm2 were higher than that of the single UV-B radiation. It was suggested that the suitable dose of low-energy ion beams pretreatment to wheat seeds could change its physiological characteristics at seedlings stage to alleviate the damage effects from UV-B radiation.  相似文献   

5.
Radionuclides such as 131I, 134Cs, 137Cs, and 239,240Pu in Korean rainwater have been analyzed by Korea Research Institute of Standards and Science (KRISS) since the Fukushima nuclear power plant accident in March 2011 to investigate the activity level, distribution pattern, and temporal variation and to assess the radiation dose the public is exposed to. The concentration of 131I in the Korean rainwater samples varied between 0.033 (minimum detectable activity; MDA) and 1.30 Bq kg?1 and the concentrations tended to decrease exponentially with time. The concentrations of 134Cs and 137Cs in rainwater ranged from 0.01 to 334 ± 74 and 0.29 ± 0.01 to 276 ± 1 mBq kg?1, respectively. The mean activity ratio of 137Cs/134Cs in the rainwater samples collected from April 18 to May 12 was estimated to be 0.44 ± 0.21, and this value is lower than that (ca. 1) observed in Fukushima, Japan, when there was an escape from the nuclear reactors. When an attempt was made to analyze Pu isotopes in rainwater samples, no Pu isotopes were detected above the MDA in any of the rainwater samples. Although the locations investigated were different from Asia to Europe, the concentrations of 131I, 134Cs and 137Cs in the rainwater are comparable, which suggests a global contamination of 131I, 134Cs, and 137Cs occurred because of the Fukushima nuclear power plant accident.  相似文献   

6.
A multivariate calibration procedure based on singular value decomposition (SVD) and the Ho-Kashyap algorithm is used for the tensammetric determination of the cationic detergents Hyamine 1622, benzalkonium chloride (BACl), N-cetyl-N,N,N-trimethylammonium bromide (CTABr) and mixtures of CTABr and BACl. The sensitivity and accuracy depend strongly on the nature of the detergent. Acceptable accuracy is obtained with a two-step calculation procedure in which calibration constants for the total concentration range of interest are used to guide the choice of a more specific set of calibration constants which are valid for a much smaller concentration span. For Hyamine 1622, concentrations in the range 5 × 10?6?2 × 10?4 M could be determined with an accuracy of ± 10?6 M. For CTABr, these numbers were 3 × 10?6?2 × 10?4 M and ± 5 × 10?7 M; for BACl, they were 2 × 10?3?9 × 10?2 g l?1 and ± 1 × 10?3 g l?1. In the mixtures of CTABr and BACl, the accuracies were ± 3 × 10?6 M and × 1 × 10?3 g l?1, respectively.  相似文献   

7.
Natural radioactivity in soil and vegetable samples in cultivated land in the vicinity of an active phosphate fertilizer plant in Kaduna, Nigeria was carried out to assess the potential radiological impact of the plant on its immediate environment. The activity counting was carried out using sodium iodide gamma spectrometry. The annual committed effective dose for two vegetables in the farmlands due to uranium (238U) and thorium (232Th) was assessed. The mean activity concentration of radionuclides in the soil samples ranges from 20.5±7.3 to 31.6±4.1 Bq kg?1 for 226Ra, 19.6±1.6 to 53.2±3.7 Bq kg?1 for 232Th and 203.9±6.3 to 253.6±9.5 Bq kg?1 for 40K. The annual intake of 238U and 232Th from consumption of okra were 1.9 Bq kg?1 and 5.22 Bq kg?1 and for tomatoes 2.66 Bq kg?1 and 5.1 Bq kg?1 respectively. The committed effective doses from consumption of okra and tomatoes were 0.1 μSv y?1 and 0.12 μSv y?1 respectively.  相似文献   

8.
Summary Radionuclide (137Cs, 238U, 232Th and 40K) concentrations were determined in a sediment trap and bottom sediment samples collected from a station at the eastern Turkish coast of the Black Sea. The specific activity of the 137Cs radionuclide in the settling particles ranged from 0.04±0.01 to 0.10±0.02 Bq. g-1dry weight. The calculated flux rate of the 137Cs was between 0.37 and 2.59 Bq. m-2. d-1in the sampling periods of 2002 and 2003. The 137Cs concentration in the bottom sediment profile were between 0.039±0.013-9.083±0.017 Bq. g-1dry weight in the same station. The vertical profile of the radionuclides suggests that they have little mobility during the 17 years after the Chernobyl accident.  相似文献   

9.
In the first part of this paper, the influence of radon (222Rn) exhalation rate from walls and air exchange upon its concentration in room air was considered using a simple mathematical room model. The exhalation rates have been determined in ten low ventilated rooms of ten villas in Jeddah city (Western Province) of Saudi Arabia. An electroprecipitation method has been applied for the determination of the 222Rn gas concentration in these rooms. The mean 222Rn gas concentration was found to be 46.80±8.80 Bq m?3. The mean 222Rn exhalation rate was estimated to be 20.11±6.90 Bq m?2 h?1. The mean inhalation dose due to the exposure to 222Rn gas was calculated to be 1.18±2.30 mSv y?1.The second part of this paper deals with a study of natural radionuclide contents of samples collected from the building materials of these rooms under investigations in part one. Analyses were performed in Marinelli beakers with a gamma spectroscopy system to quantify radioactivity concentrations. The collected samples revealed the presence of the uranium–radium (226Ra) and thorium (232Th) radioisotopes as well as 40K. The mean activity concentration of 226Ra, 232Th and 40K was determined to be 48.30±5.08, 43.90±5.63 and 223.90±7.55 Bq kg?1, respectively. These activities amount to a radium equivalent (Raeq) of 125.96±15.90 Bq kg?1 and to a mean value of external hazard index (Hex) of 0.34±0.04.  相似文献   

10.
A set of measurements have been conducted to determine the levels activity of gamma-emitters present in infant formula. The study of different samples shows the presence of the following radionuclides: 226Ra, 232Th and 40K with respectively average activity of 0.52 ± ?0.087, 0.51 ± 0.062, 371.98? ± 3.68 Bq/kg. The mean annual doses lead to 0.62 and 0.24 mSv/year whereas the total risk is about 7.91 × 10?6 and 5.32 × 10?6 respectively ≤ 1 year and 1–2 years old infants. The obtained results show that no significant radiation dose and no risk to the infants due to consumption of these milks.  相似文献   

11.
Abstract

We examined the ability of Bothrops jararaca venom (12.5?mg/kg) injected intraperitoneally (i.p.) to cause acute kidney injury (AKI) in rats. Blood urea and creatinine (AKI biomarkers, in g dL?1) were elevated after 2?h in venom-treated rats (urea: from 0.41?±?0.1 to 0.7?±?0.03; creatinine from 46.7?±?3.1 to 85?±?6.7; p?<?0.05; n?=?3 each), with no change in circulating reduced glutathione. Venom-treated rats survived for ~6?h, at which point platelets were reduced (×103 µL?1; from 763.8?±?30.2 to 52.5?±?18.2) whereas leukocytes and erythrocytes were slightly increased (from 4.7?±?0.3 to 6.6?±?0.1?×?103?µL?1 and from 8.38?±?0.1 to 9.2?±?0.09?×?106?µL?1, respectively; p?<?0.05); blood protein (5.2?±?0.4?g dL?1) and albumin (2.7?±?0.1?g dL?1) were normal, whereas blood and urinary urea and creatinine were increased. All parameters returned to normal with antivenom given 2?h post-envenomation. The i.p. injection of venom caused AKI similar to that seen with other routes of administration.  相似文献   

12.
A validated kinetic spectrophotometric method has been developed for the determination of losartan potassium in pure and dosage forms. The method is based on oxidation of the losartan potassium with alkaline potassium permanganate at room temperature (25 ± 1 °C). The reaction is followed spectrophotometrically by measuring the increase in absorbance with time at 603 nm, and the initial rate, fixed time (at 12.0 min) and equilibrium time (at 90.0 min) methods are adopted for constructing the calibration graphs. All the calibration graphs are linear in the concentration range of 7.5–60.0 μg mL?1 and the calibration data resulted in the linear regression equations of n? = ?6.422 × 10?7 + 1.173 × 10?5 C, A =3.30 × 10?4 + 5.28 × 10?3 C and A = ?2.09 × 10?2 + 1.05 × 10?1 C for initial‐rate, fixed time and equilibrium time methods, respectively. The limits of detection for initial rate, fixed time and equilibrium time methods are 0.71, 0.21 and 0.19 μg mL?1, respectively. The activation parameters such as Ea, ΔH?, ΔS?, and ΔG? are also determined for the reaction and found to be 87.34 KJ mol?1, 84.86 KJ mol?1, 50.96 JK?1 mol?1 and ?15.10 KJ mol?1, respectively. The variables are optimized and the proposed methods are validated as per ICH guidelines. The method has been applied successfully to the estimation of losartan potassium in commercial tablets. The performance of the proposed methods was judged by calculating paired t‐ and F‐ values. The analytical results of the proposed methods when compared with those of the reference method show no significant difference in accuracy and precision and have acceptable bias.  相似文献   

13.
A novel diclofenac ion-selective electrode has been prepared and used in pharmaceutical analysis. The ion-associate of diclofenac with basic dye (crystal violet) was used as the membrane carrier. Among the four different solvent mediators tested, dibutylphthalate (DBP) exhibited proper behavior including the Nernstian slope of the calibration curve, fast response time and good reproducibility of the emf values. The electrode exhibits a Nernstian slope of 59 ± 1 mV decade?1 for diclofenac in the concentration range 5.0 × 10?5-5.0 × 10?2 M with the limit of detection of 2.5 × 10?5 M. The electrode displays good sensitivity with the respect to a number of common inorganic and organic species. It can be used in a pH range of 6–11. The membrane sensor was successfully applied to the determination of diclofenac in capsules and for its recovery from urine samples.  相似文献   

14.
The complexation of thiabendazole (TBZ) with the cucurbit[6]uril (Q[6]), cucurbit[7]uril (Q[7]) and symmetric tetramethyl-cucurbit[6]uril (TMeQ[6]) in aqueous solution has been investigated using UV–vis and fluorespectrometry. The experimental results show 1:1 host–guest inclusion complexes at pH 6.5 for all three macrocyclic hosts, and the corresponding formation constants by UV and fluorescence methods are (5.37?±?1.05)?×?104?L?mol?1 and (1.47?±?0.41)?×?104?L?mol?1 for the Q[6]-TBZ system (7.76?±?0.51)?×?104?L?mol?1 and (9.36?±?0.22)?×?104?L?mol?1 for the Q[7]-TBZ system (1.28?±?0.78)?×?104?L?mol?1 and (2.69?±?0.55)?×?104?L?mol?1 for the TMeQ[6]-TBZ system, respectively. Based on the enhancement of the fluorescence intensity of TBZ with the addition of Q[n]s in neutral media, a fluorespectrometry method for the determination of TBZ in aqueous solution in the presence of Q[n] was established. In the range of 6.0?×?10?8?mol?L?1–8.0?×?10?6?mol?L?1 a linear relationship was obtained between fluorescence intensity and TBZ concentration. The detection limit was found to be between 5.51 and 8.85?×?10?9?mol?L?1. The interference of coexisting ions was found to be slight. The proposed method has been successfully applied to the determination of TBZ in different aqueous solutions with satisfactory recoveries of 92–103%. The method seems to be suitable for environmental water analysis.  相似文献   

15.
《Electroanalysis》2006,18(21):2070-2078
A highly selective potentiometric sensor for thiocyanate ion based on the use of a newly synthesized organo‐palladium ion exchanger complex dispersed in a plasticized poly(vinyl chloride) membrane is described. The sensor displays a Nernstian response (?57.8±0.2 mV decade?1) over a wide linear concentration range of thiocyanate (1.0×10?6–1.0×10?1 mol L?1 ), low detection limit (6.3×10?7 mol L?1), fast response (20 s), stable potential readings (±0.4 mV), good reproducibility (±0.9%), long term stability (8 weeks), high precision (±0.7%) and applicability over a wide pH range (4–10). Negligible interferences are caused by F?, Cl?, I?, Br?, NO3?, NO2?, CN?, SO42?, S2O32?, PO43?, citrate, acetate and oxalate ions. Under hydrodynamic mode of operation (FIA), the calibration slope is ?51.1±0.1 mV decade?1, the linear response range is 1.0×10?5–1.0×10?1 mol L?1 SCN? and the sample throughput is 40–45 per hour. The sensor is satisfactory used for manual and flow injection potentiometric determination of SCN? in the saliva and urine of cigarette smokers and non smokers. The data agree fairly well with results obtained by the standard spectrophotometric technique. Direct potentiometry and potentiometric titration of SCN? with Ag+ are also monitored with the sensor.  相似文献   

16.
The activity concentration of primordial radionuclides 226Ra, 232Th, and 40K in soil samples of Thirthahalli taluk were measured systematically by using a low background HPGe detector coupled to 16 K MCA. The measured activity concentration of 226Ra lies between 5.1?±?0.2 and 79.5?±?1.7 Bq kg?1with an average activity of 25.99 Bq kg?1, 232Th ranges from 5.1?±?0.3 to 95.3?±?2.2 Bq kg?1with an average activity of 33.60 Bq kg?1and that of 40K varies from 18.3?±?1.5 to 833.4?±?17.5 Bq kg?1with an average activity of 175.52 Bq kg?1. Higher concentration of these radionuclides were found in the soil samples where the regional geology is granites. The consequential gamma dose and the corresponding radiation hazard was also estimated and is found to be within the permissible limits. The possible radiological impact on the public was also determined and these results are presented in this paper.  相似文献   

17.
Three simple, rapid, and sensitive ion-selective electrodes for indirect determination of free formaldehyde in urea glue and wastewater have been developed. The methods are based on the formation of the membrane sensors 2,4-dinitrophenylhydrazine-phosphtungestic acid (DNPH-PTA), 2,4-dinitrophenylhydrazine-phosphomolybdic acid (DNPH-PMA), and 2,4-dinitrophenylhydrazine-tetraphenylborate (DNPH-TPB) as neutral carriers. The sensors are stable and show fast potential responses of 30?s, and near-Nernstian cationic slopes of 56.2?±?0.5, 54.3?±?0.5, and 53.8?±?0.4?mV per decade of activity between pH 0.5 and 3.5 over a wide range of 2,4-dinitrophenylhydrazine concentrations (1?×?10?5 to 1?×?10?2?M). These sensors were used for indirect determination of formaldehyde over concentration range (1?×?10?4 to 1?×?10?1?M). The selectivity coefficients of the developed sensors indicate excellent selectivity for 2,4 DNPH over a large number of organic and inorganic species. The mediator o-nitrophenyloctyl ether has a significant affect on the lifetime of the fabricated sensors. The analytical applications of the proposed sensors showed good results for indirect determination of formaldehyde in formaldehyde solutions, wastewater solutions, and free formaldehyde in urea-formaldehyde liquid and powder glues. The results were compared favourably with that obtained by ASTM, colorimetric, and British Standard methods.  相似文献   

18.
A hanging copper amalgam drop electrode (HCADE) is used for the determination of traces of iodide by cathodic stripping voltammetry. The cathodic stripping peak of copper(I) iodide from the HCADE is better defined than that of mercury(I) iodide from a hanging mercury drop electrode. Optimum conditions and interferences are reported. With a 3-min deposition time at ?0.1 V vs. SCE, the calibration plot is linear up to 2 × 10?6 mol dm?3 iodide. The detection limit for iodide with the HCADE under voltammetric conditions is 4 × 10?8 mol dm?3; this is lowered to 8 × 10?9 mol dm?3 by using the differential pulse stripping technique.  相似文献   

19.
The electrochemical behavior of D ‐penicillamine (D ‐PA) studied at the surface of ferrocene carboxylic acid modified carbon paste electrode (FCAMCPE) in aqueous media using cyclic voltammetry and double step potential chronoamperometry. It has been found that under optimum condition (pH 7.00), the oxidation of D ‐PA at surface of such an electrode is occurred about 420 mV less positive than that an unmodified carbon paste electrode (CPE). The catalytic oxidation peak current was linearly dependent on the D ‐PA concentration and a linear calibration curve was obtained in the ranges 7.5×10?5 M – 1.0×10?3 M and 6.5×10?6 M?1.0×10?4 M of D ‐PA with cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods respectively. The detection limits (3σ) were determined as 6.04×10?5 M and 6.15×10?6 M. This method was also used for the determination of D ‐PA in pharmaceutical preparation (capsules) by standard addition method.  相似文献   

20.
A kinetic spectrophotometric method has been described for the determination of metoprolol tartrate in commercial dosage forms. The procedure is based on the reaction of the drug with 1‐chloro‐2, 4‐dinitrobenzene (CDNB) in dimethylsulfoxide (DMSO) at 100 ± 1 °C. The reaction is investigated by measuring the change in absorbance with time at 420 nm. Fixed‐time (ΔA) and equilibrium methods are chosen for obtaining the calibration curves. Both calibration curves were found to be linear over the concentration range of 5‐60 μg mL?1. The regression analysis of calibration data resulted in the linear regression equations of ΔA = ?1.608 × 10?4 + 3.96 × 10?3 C and A = 7.31 × 10?4 + 1.90 × 10?2 C for fixed time (ΔA) and equilibrium methods, respectively. The limit of detection (LOD) for fixed time and equilibrium methods are 1.16 and 0.415 μg mL?1, respectively. The method has been successfully applied to the quantitation of metoprolol tartrate in commercial dosage forms. Statistical comparison of the results shows that there is no significant difference between the proposed methods and El‐Ries's spectrophotometric method.  相似文献   

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