Levels and effects of natural radionuclides in soil samples of Garhwal Himalaya

Distribution of natural radionuclide gives significant parameter to assess the presence of gamma radioactivity and its radiological effect in our environment. Natural radionuclides are present in the form of ²²⁶Ra, ²³²Th and ⁴⁰K in soil, rocks, water, air, and building materials. Distribution of natural radionuclides depends on the type of minerals present in the soil and rocks. For this purpose gamma spectrometer is used as tool for finding the concentration of these radionuclides. The activity concentration of naturally occurring radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K in these soil samples were found to vary from of 8 ± 1 Bq/kg to 50 ± 10 Bq/kg with an average 20 Bq/kg, 7 ± 1–88 ± 16 Bq/kg with an Average 26 Bq/kg and 115 ± 18–885 ± 132 Bq/kg with an average 329 Bq/kg, respectively. In this paper, we are presenting the radiological effect due to distribution of natural radionuclide present in soil of Garhwal Himalaya.     

Radiolabeling of EGCG with 125I and its biodistribution in mice

The aim of the present study was to label EGCG with ¹²⁵I and to determine its radiopharmaceutical potential in mice. EGCG was labeled with ¹²⁵I using the iodogen method. The labeling yield and the radiochemical purity of ¹²⁵I–EGCG were determined by radio thin-layer chromatography (RTLC). The Labeling yield was approximately 89.4 %. The radiochemical purity was approximately 96.4 %. The biodistribution studies of the labeled compound (specific activity; 0.47 TBq/μg) were performed in male Kunming mice. The uptakes of ¹²⁵I–EGCG in some organs were determined at different time after injection to the mice. The radioactivity in each organ was counted and the percentage of injected activity per gram of tissue weight (%ID/g) for each organ and blood was calculated. Incorporation of radioactivity in the various tissue/organ was confirmed by microautoradiography. ¹²⁵I–EGCG uptake in the stomach and salivary gland was higher than other organ/tissue. The black silver grains was concentrated in the nucleus, cytoplasm, intercellular substance and capillaries of that various organs, and its unevenly distributed. Thus, ¹²⁵I–EGCG may be radiopharmaceutical for the imaging of the stomach and salivary gland.     

Radiosynthesis of 10-(2-[18F]fluoroethoxy)-20(S)-camptothecin as a potential positron emission tomography tracer for the imaging of topoisomerase I in cancers

The preparation of 10-(2-[¹⁸F]fluoroethoxy)-20(S)-camptothecin, a potential positron emission tomography tracer for the imaging of topoisomerase I in cancers, is described. 10-(2-[¹⁸F]Fluoroethoxy)-20(S)-camptothecin was synthesized by the [¹⁸F]fluoroalkylation of the corresponding hydroxy precursor molecule with 2-[¹⁸F]fluoroethyl bromide ([¹⁸F]FEtBr) in dimethylsulfoxide (DMSO) at 55 °C for 20 min; this was followed by purification using high performance liquid chromatography (HPLC) with a total preparation time of 60 min. The overall radiochemical yield was approximately 5.4–12 % (uncorrected), and the radiochemical purity was above 96 %.     

Certified reference material IAEA-418: 129I in Mediterranean Sea water

A certified reference material designed for the determination of ¹²⁹I in seawater, IAEA-418 (Mediterranean Sea water) is described and the results of certification are presented. The median of ¹²⁹I concentration with 95% confidence interval was chosen as the most reliable estimates of the true value. The median, given as the certified value, is 2.28 × 10⁸ atom L^?1 (95% confidence interval is (2.16–2.73) 10⁸ atom L^?1), or 3.19 × 10^?7 Bq L^?1 (95% confidence interval is (3.02–3.82) × 10^?7 Bq L^?1). The material is intended to be used for standardization procedures applied in accelerator mass spectrometric laboratories. It is available in 1 L units and may be ordered via IAEA web side (www.iaea.org).     

Epithermal instrumental neutron activation analysis in conjunction with anti-coincidence gamma-ray spectrometry for investigating iodine levels in Canadian foods

In order to reduce interferences from high activities of ²⁴Na, ⁵⁶Mn, ⁸²Br, and ³⁸Cl as well as to improve detection limits, precision, and accuracy of measuring iodine levels in biological materials, foods and diets in particular, an epithermal instrumental neutron activation analysis (EINAA) method in conjunction with anti-coincidence (EINAA-AC) gamma-ray spectrometry was employed. The Compton scattering background in the region of the 442.9-keV photopeak of ¹²⁸I was significantly suppressed by anti-coincidence counting. In order to validate the EINAA-AC method as well as to evaluate its broad applicability to diverse types of biological material, 17 NIST and IAEA reference materials containing very low to high levels of iodine as well as interfering elements were analyzed by the EINAA-AC method. The samples were irradiated in the cadmium-lined pneumatic site at a neutron flux of 2 × 10¹¹ cm^?2 s^?1 of the Dalhousie University SLOWPOKE-2 Reactor (DUSR) facility for 10 or 20 min followed by 1-min decay and 30-min counting. The detection limit for iodine by EINAA-AC was improved by a factor of 2–5 compared to EINAA depending on the sample matrix and other factors, and a limit of 3–5 μg kg^?1 was achieved for low-salt foods. We found the RSD to be about ±5 % above 200, increasing to ±10 % at 20, and then to greater than ±30 % at about 5 μg kg^?1 iodine levels.     

Separation of 3H, 14C, 32P, 35S, 125I, and 131I in radioisotope waste

Measurement of ³H, ¹⁴C, ³²P, ³⁵S, ¹²⁵I, and ¹³¹I in radioisotope (RI) waste materials such as the vials, pipette tips, tubes, syringes, and paper generated from the industrial, medical, educational, and research organizations were conducted by a wet oxidation method. Counts were obtained by a liquid scintillation counter for ³H, ¹⁴C, and ³²P; a gas proportional counter for ³⁵S; a low energy photon spectroscopy for ¹²⁵I; and an HPGe detector for ¹³¹I. After the treatment of approximately 20 g of the sample, the counting value was determined to obtain a minimum detectable activity (MDA) of approximately 1 × 10^?3 ~ 5 × 10^?2 Bq/g. The specific activities of shor-half-life RIs (³²P, ³⁵S, ¹²⁵I, and ¹³¹I) were not detectable and/or resulted in a low value (<1 Bq/g). The waste containing ³H and ¹⁴C was observed to have the specific activities in the range of 10^?2–10⁵ and 10^?2–10⁴ Bq/g, respectively.     

Quantitative LC Analysis of Cyclosporine A in Ocular Samples

An isocratic reversed-phase HPLC method with ultraviolet detection at 205 nm has been developed for analysis of cyclosporine A (CyA) in rabbit ocular samples. Neither internal standard nor extraction was needed for sample preparation. Acetonitrile (ACN; 1 mL) was added to 250 μL aqueous and vitreous samples to precipitate proteins. The supernatant was dried and the residue was reconstituted in mobile phase and injected for HPLC analysis. Chromatography was performed on an octadecyl silane-A (ODSA) C₁₈ (4.6 × 250 mm, 5 μm) column. The column temperature was fixed at 70 °C and the mobile phase was ACN 65%, methanol 20% and water 15% at a flow rate of 1.5 mL min^?1. The calibration curve for CyA in rabbit ocular samples was linear over the concentration range 0.2 and 10 μg mL^?1 with a correlation coefficient of 0.9992. Intra-day and inter-day precision were 4.61–7.83% and 5.27–10.70%, respectively. Intra-day and inter-day accuracy were 89.2–108% and 83.4–111%, respectively. The limits of detection (LOD) and quantification (LOQ) were 5.7 and 38 ng mL^?1, respectively. The method was successfully used for analysis of CyA in real aqueous and vitreous humor samples from New Zealand albino rabbits. The method is therefore suitable for analysis of CyA in ocular samples.     

Determination of Copper in Human Urine by RP-LC After Pre-column Derivatization with Neocuproine and Use of Monolithic Column

A selective sensitive RP-LC–UV/VIS method with pre-column derivatization was developed for the determination of copper in human urine at a trace level. This method is based on the selective reaction of 2,9-dimethyl-1,10-phenanthroline (neocuproine) with copper(I) to produce a yellow-orange hydrophobic complex in a neutral or slightly acidic buffer solution (adjusted to pH 5.9). Copper(II) was reduced to copper(I) ions by ascorbic acid as a weak reducer, which was added both to urine sample and mobile phase, respectively. A hydrophobic copper(I)–neocuproine chelate was determined by RP-LC–UV/VIS using a monolithic column Chromolith Performance RP-8e (100 × 4 mm I.D.) at 30.0 ± 0.1 °C with a methanol: aqueous buffer (pH 5.9, ammonium acetate and ascorbic acid 2.8 mmol L^?1) mobile phase at flow rate of 2.00 mL min^?1. Sample injection volume was 20 μL and detection was done at 453 nm. The method was validated over a concentration range of 0.09–11.50 μmol L^?1. The LOD of copper in human urine was found to be 0.07 μmol L^?1 concentration level, suitable for clinical analysis. The precision of the results, reported as the RSD, was below 4.6 % for copper concentration within range 0.5–5.0 μmol L^?1 in the spiked human urine samples.     

LC–APCI–MS–MS for the Determination of Celastrol in Human Whole Blood

A rapid, sensitive high-performance liquid chromatographic tandem mass spectrometric (HPLC–MS–MS) assay has been developed and validated for the quantitative determination of celastrol in human whole blood using hydrocortisone as an internal standard (I.S.). The celastrol and I.S. were extracted from human whole blood with ethyl acetate. The separation was performed by reversed-phase HPLC using an isocratic mobile phase consisting of 5 mmol L^?1 aqueous ammonium acetate containing 0.05% acetic acid/methanol (25:75, v/v) on a XDB-C₁₈ column (150 mm × 4.6 mm I.D., 5 μm). Detection was by negative atmospheric pressure chemical ionization (APCI) and ion trap tandem mass spectrometry in multiple reaction monitoring (MRM) mode with a transition of m/z 449.4 → 405.1 for celastrol, and 419.2 → 329.1 for I.S. The calibration curve was linear (r ² = 0.9967) in the concentration range of 1.0–200.0 ng mL^?1 in human whole blood with a limit of quantification of 1.0 ng mL^?1. Intra-day and inter-day relative standard deviations (RSDs) were less than 8.5 and 10.1%. The mean extraction recovery was 89.2% for celastrol and 92.6% for I.S. This assay can be used to determine trace celastrol in human whole blood.     

Highly Sensitive Flow-Injection Chemiluminescence Detection of Carbonyl Compounds in Wine Samples

A modified Trautz–Schorigin reaction, by using tannic acid-H₂O₂ system for the oxidation and determination of two kinds of carbonyl compounds was developed in this paper. It was found that formaldehyde and acetaldehyde could effectively enhance the chemiluminescence signals of tannic acid–H₂O₂ system in alkaline medium. Under optimized conditions, the proposed method has a linear range of 7 × 10^?9–1 × 10^?4 mol L^?1 for formaldehyde and 1 × 10^?8–1 × 10^?4 mol L^?1 for acetaldehyde with detection limits of 9 × 10^?11 and 3 × 10^?10 mol L^?1, respectively. The relative standard deviations for 15 repeated measurements of 1 × 10^?6 mol L^?1 HCHO and CH₃CHO are 1.13% and 1.65%, respectively. Analysis time per sample is 35 seconds. A comparison of results found by the proposed method with those obtained by a standard reference method provided good agreement. The proposed method is simple, rapid, convenient, and sensitive.     

Use of Capillary Zone Electrophoresis and Micellar Electrokinetic Chromatography for Separations of Anthraquinone Derivatives

The behavior of seven hydroxy anthraquinone derivatives was studied by capillary zone electrophoresis and micellar electrokinetic chromatography. The effects of buffer pH (6.5–10.8) and sodium dodecyl sulfate concentration (10–20 mmol L^?1) on the effective mobilities of the analytes and their separation were tested. A comparison of the two optimized separation systems showed that micellar electrokinetic chromatography was superior as it permits separation of all the seven analytes within 15 min, using 15 mmol L^?1 sodium dodecyl sulfate in 10 mmol L^?1 tetraborate buffer, pH 8.5, at a voltage of 20 kV. The calibration curves were linear in the concentration range from 5.0 · 10^?7 to 5.0 · 10^?4 mol L^?1 for most of the analytes, at a detection wavelength of 254 nm. LOD and LOQ values of the analytes were in the ranges of 2.10 · 10^?7–1.28 · 10^?6 mol L^?1and 6.99 · 10^?7–4.25 · 10^?6 mol L^?1, respectively. The proposed separation conditions were applied to determination of 1,2-dihydroxy anthraquinone (alizarin) and 1,2,4-trihydroxy anthraquinone (purpurin) in Rubia tinctorum aglycone and of the recently described 1-acetyl-2,4,5,7-tetrahydroxy-9,10-anthraquinone and 1-acetyl-2,4,5,7,8-pentahydroxy-9,10-anthraquinone in the mycelium of fungi Geosmithia lavendula.     

Development of an ion-exchange method for separation of radioiodine from tellurium and antimony and its application to the production of 124I via the 121Sb(α,n)-process

A novel anion-exchange chromatographic method for separation of radioiodine from an antimony target irradiated with ³He- or α-particles was developed, with separation yield of radioiodine amounting to 90 ± 5 % and its decontamination factor from the Te and Sb radionuclides to ~10⁴. The optimized separation method developed was then applied to the production of ¹²⁴I via the ¹²¹Sb(α,n)¹²⁴I process using a highly enriched ¹²¹Sb target. Quality control tests showed that the separated ¹²⁴I occurred >99 % as iodide and the longer lived impurities ¹²⁶I and ¹²⁵I amounted to 0.16 % and <0.05 %, respectively. The trace level of inactive Sb impurity was determined by ICP–OES.     

An Efficient Separation Method of Polysaccharides: Preparation of an Antitumor Polysaccharide APS-2 from Auricularia polytricha by Radial Flow Chromatography

Auricularia polytricha is an edible mushroom, quite popular in China. Modern pharmacology research indicate that A. polytricha polysaccharides possess antitumor and immunomodulatory activities. In this paper, an antitumor Auricularia polytricha polysaccharide (APS)-2 was purified by radial flow chromatography (RFC) in a column of 500 mL bed-volume (40 cm i.d × 15 cm) packed with DEAE52-cellulose anion ion-exchange resin. The optimal separation conditions were: sample flow-velocity 15–20 mL min^?1, sample volume 160–200 mL, and elution with distilled water and 0.2 M NaCl at a velocity of 35–45 mL min^?1. The yield and content of APS-2 obtained under these conditions were 182 mg g^?1 total polysaccharides and 98.35 %, respectively. The study provides guidelines for the separation and purification of polysaccharides using a radial flow chromatography column.     

Simultaneous Quantitative Analysis of Shikonin and Deoxyshikonin in Rat Plasma by Rapid LC–ESI–MS–MS

The purpose of this article was to develop a rapid and robust LC–MS–MS method for quantifying shikonin and deoxyshikonin simultaneously in rat plasma using emodin as internal standard. The LC system consisted of an Agilent ZORBAX SB-C18 (1.8 μm, 250 × 4.6 mm, 20 °C) column. Elution with an isocratic mobile phase consisted of methanol/10 mM ammonium acetate in water/acetonitrile containing 0.05% formic acid (45:10:45, v/v/v) at a flow rate of 0.8 mL min^?1 yielded sharp, high-resolved peaks within 12 min. The lower limits of quantitation were 0.5 ng mL^?1 for shikonin, and 8 ng mL^?1 for deoxyshikonin. Correlation coefficient (r) values for the linear range of two analytes were greater than 0.99. Assay precision was <13% and accuracy was 87–99%. This newly developed method was used to the pharmacokinetic studies of the shikonin analogues in rats after intravenous administration (n = 4).     

Comparative study of carbon paste electrodes modified by new pentaaza macrocyclic ligands and gold nanoparticles embedded in three-dimensional sol–gel network for determination of trace amounts of Ag(I)

Two new Ag(I) chemically modified carbon paste electrodes were prepared with comparative potentiometric study of 1,3,6,10,13-pentaaza-2,14-(2,6-pyridyl)-cyclotetradecane-4,12-dione (PPCT) and 1,3,6,9,11,12-pentaaza-2,13-(2,6-pyridyle)-bicycle[2,2,9]pentadecane-4,11-dione (PPBP) as ionophore. These sensors have been modified with sol–gel–Au nanoparticles to obtain a wide concentration range for potentiometric determination of Ag(I) in aqueous solutions. The sensors exhibit significantly enhanced selectivity toward Ag(I) ions over a wide concentration range of 4.0 × 10^?9–2.2 × 10^?2 and 2.2 × 10^?7–2.0 × 10^?2 mol L^?1 with a lower detection limit of 2.5 × 10^?9 and 2.0 × 10^?7 mol L^?1 for PPCT and PPBP modified electrodes respectively. The electrodes are highly selective to Ag(I) ions over a large number of mono, bi, and tri-valent cations. These electrodes were successfully used as indicator electrode for potentiometric determination of silver in sulphadiazine (burning cream) and radiological film.     

Determination of Ammonia in Water Using Flow Injection Analysis with Automatic Pervaporation Enrichment

Abstract

An automated ammonia monitoring system has been developed by putting a pervaporation unit in an enrichment cycle used in flow injection analysis mode. In the proposed system, an enrichment cycle was equipped to enable the adjustment for the measuring range of ammonium by controlling the duration of the enrichment circulation. Therefore, the system was capable to determine ammonia in both the surface water with low ammonia concentration and the ammonia-rich wastewater with the linear dynamic range of 0.05–15 mg l^?1 and 15–50 mg l^?1, respectively. The relative standard deviations were less than 1.9% and the quantification limit is as low as 0.03 mg l^?1. The sampling frequency is 8–10 h^?1.     

The effect of Nb and Ni addition on crystallization behavior of amorphous–nanocrystalline Fe–Cr–B–Si alloys

The crystallization behavior of amorphous Fe–Cr–B–Si alloys in the presence of Ni and Nb elements was the goal of this study. In this regard, four different amorphous–nanocrystalline Fe₄₀Cr₂₀Si₁₅B₁₅M₁₀ (M=Fe, Nb, Ni, Ni_0.5Nb_0.5) alloys were prepared using mechanical alloying technique up to 20 h. Based on the achieved results, in contrast to Fe₅₀Cr₂₀Si₁₅B₁₅ alloy, the amorphous phase can be successfully prepared in the presence of Ni and Nb in composition. Although the crystallization mechanism of prepared amorphous phase in different alloys was the same, the Fe₄₀Cr₂₀Si₁₅B₁₅Nb₁₀ alloy showed higher thermal stability in comparison with other samples. The crystallization activation energy of this amorphous alloy was estimated about 410 kJ mol^?1 which was much higher than Fe₄₀Cr₂₀Si₁₅B₁₅Ni₁₀ (195.5 kJ mol^?1) and Fe₄₀Cr₂₀Si₁₅B₁₅Ni₅Nb₅ (360 kJ mol^?1) samples. The calculated values of Avrami exponent (1.5 < n < 2.2) indicated that the crystallization process in different alloying systems is the same and to be governed by a three-dimensional diffusion-controlled growth.     

Determination of ultratrace amounts of plutonium in high saline groundwater by inductively coupled plasma mass spectrometry

For determination of ultratrace amounts of plutonium in high saline groundwater, large-volume sampling and preconcentration are necessary. However, traditional co-precipitation methods, such as Fe(OH)₃, Ca(OH)₂–Mg(OH)₂ and hydroxide-carbonate co-precipitation, are unable to meet the requirements of preconcentration of the ultratrace plutonium in high saline groundwater. In this paper, the ultratrace plutonium in high saline groundwater was concentrated by sequential co-precipitation with MnO₂ and Fe(OH)₃, and purified by two-stage anion-exchange separation on Dowex1 × 4 resin column. Quadrupole ICP-MS was employed for the determination of ²³⁹Pu with ²⁴²Pu spiked. After co-precipitation and purification, the major matrix elements were significantly decreased to μg mL^?1 level and decontamination factor of uranium is better than 10⁶. The detection limit for ²³⁹Pu in 50 L high saline water is 2.1 × 10^?16 g L^?1. Three high saline fountain samples (total dissolved solids more than 20 g L^?1) from Dunhuang region of China were analyzed using this method. The concentrations of ²³⁹Pu in these samples were 0.48 ± 0.2 × 10^?15, 1.40 ± 0.10 × 10^?15 and 2.13 ± 0.21 × 10^?15 g L^?1 respectively. The recovery obtained for 7 pg of ²⁴²Pu spiked into real high saline-water samples was all above 70 %.     

Radioactivity levels and radiation hazard of healing mud from San Diego River, Cuba

Healing mud core samples were collected in the San Diego River (Southwest Cuba), in order to determine the behaviour of the radioactivity levels of ²²⁶Ra, ¹³⁷Cs, ²³²Th and ⁴⁰K and to evaluate their possible radiological impact on peloide therapeutic uses. The radionuclide concentration ranges in healing mud profiles on Bq kg^?1 dry weight varied as follows: ²²⁶Ra = 22–26, ¹³⁷Cs = 4.6–33.0, ²³²Th = 18–31 and ⁴⁰K = 208–433. The calculated average radium equivalent activity (82 Bq kg^?1), total absorbed dose rate (40 nGy h^?1), external hazard index (0.23), annual gonadal dose equivalent (280 μSv h^?1) and annual effective dose equivalent (48.5 μSv y^?1) are less than international recommended values. Hence, the levels of radioactivity in healing muds from San Diego River are not an impediment for its use for medical proposes.     

Validation of an assay for the determination of levoglucosan and associated monosaccharide anhydrides for the quantification of wood smoke in atmospheric aerosol

Biomass burning is becoming an increasing contributor to atmospheric particulate matter, and concern is increasing over the detrimental health effects of inhaling such particles. Levoglucosan and related monosaccharide anhydrides (MAs) can be used as tracers of the contribution of wood burning to total particulate matter. An improved gas chromatography–mass spectrometry method to quantify atmospheric levels of MAs has been developed and, for the first-time, fully validated. The method uses an optimised, low-volume methanol extraction, derivitisation by trimethylsilylation and analysis with high-throughput gas chromatography–mass spectrometry (GC–MS). Recovery of approximately 90 % for levoglucosan, and 70 % for the isomers galactosan and mannosan, was achieved using spiked blank filters estimates. The method was extensively validated to ensure that the precision of the method over five experimental replicates on five repeat experimental occasions was within 15 % for low, mid and high concentrations and accuracy between 85 and 115 %. The lower limit of quantification (LLOQ) was 0.21 and 1.05 ng m^?3 for levoglucosan and galactosan/mannosan, respectively, where the assay satisfied precisions of ≤20 % and accuracies 80–120 %. The limit of detection (LOD) for all analytes was 0.105 ng m^?3. The stability of the MAs, once deposited on aerosol filters, was high over the short term (4 weeks) at room temperature and over longer periods (3 months) when stored at ?20 °C. The method was applied to determine atmospheric levels of MAs at an urban background site in Leicester (UK) for a month. Mean concentrations of levoglucosan over the month of May were 21.4?±?18.3 ng m^?3, 7.5?±?6.1 ng m^?3 mannosan and 1.8?±?1.3 ng m^?3 galactosan. Figure

Monosaccharide anhydride levels and percent contribution to PM₁₀ from filter punches taken every 24 h at an urban background site in Leicester, analysed by GC–MS. G galactosan, M mannosan, L levoglucosan