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- Author or Editor: J. Yang x
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Abstract
A preconcentration method combined with neutron activation technique for the analysis of organic and inorganic mercury in waste water samples at ppb levels is presented. The inorganic mercury is extracted in CCl4 solution with lead diethyldithiocarbamate reagent and the organic mercury is extracted in C6H6 solution. Interfering activities of sodium and bromine are removed from the irradiated samples by this procedure. Two different solvent extraction procedures are also described in detail.
Abstract
To develop potential new Tc radiopharmaceuticals, a novel compound [99mTc(CO)2(NO)(EHIDA)]0 (EHIDA: 2,6-diethylphenylcarbamoylmethyliminodiacetic acid) has been prepared by reacting [99mTc(CO)3)(EHIDA)]− with NOBF4 both in water and acetonitrile. The conversion of [99mTc(CO)3)(EHIDA)]− to [99mTc(CO)2(NO)(EHIDA)]0 was supported by TLC, HPLC and eletrophoresis. The radiochemical purity (more than 99%) was proved by TLC and HPLC. The biodistribution in mice demonstrated that [Tc(CO)2(NO)(EHIDA)]0 showed higher uptake in blood, kidney and lung (15 min, blood: 19.24±2.95; kidney: 13.61±3.49; lung: 10.81±1.09.) but a lower uptake in liver (15 min, 5.73±0.74). The slower clearances (120 min, blood: 12.75±1.34; kidney: 13.61±3.49) from blood and kidney were also found. This research describes two methods for the conversion of [99mTc(CO)3]+ into [99mTc(CO)2)(NO)]2+ by using NOBF4 as the source of NO+ both in organic solvent and water. The latter method offers the possibility to introduce the NO-group in high yield in water.
Quantitative trait loci (QTL) for 11 morphometric body measurements of the hybrids of silver (Hypophthalmichthys molitrix) and bighead carp (H. nobilis) including body weight (BW), standard length (SL), body depth (BD), body thickness (BT), head length (HL), head depth (HD), length of ventral keel (LVK), length of pectoral fin (Lpec), length of pelvic fin (Lpel), length of caudal fin (Lcau) and space between pectoral and pelvic fins (SPP) were located on the sex average microsatellite linkage map constructed using the hybrids of a female bighead and a male silver carp, on which 15 microsatellites were newly mapped. One locus was found to be responsible for BW, LV K and SPP, respectively. As many as 6 loci were found to be responsible for HD. The variances of remaining traits were partitioned by different numbers of loci varying between 2 and 5. The variance explained each locus ranged from 9.1% to 23.8% of the total. The variance explained by all loci responsible for each measurement ranged from 17.7% to 75.1%. It was noted that multiple measurements were mapped on the same locus. For example, a region bounded by Hym435 and Hym145 was found to be responsible for all the measurements analyzed.
Abstract
The kinetics of thermal decomposition of a series of uranyl nitrate complexes with N-alkylcaprolactams (alkyl=C2H5, C4H9, C6H13, C8H17, C10H21 or C12H25) was studied by means of non-isothermal gravimetry under a nitrogen atmosphere. From the TG-DTG curves, the kinetic parameters relating to the loss of two molecules of coordinated ligand were obtained by employing two groups of methods: (I) a group of conventional methods involving the Coast-Redfern, Freeman-Carroll, Horowitz-Metzger, Dharwadkar-Karkhanavala and Doyle (modified by Zsakó) equations; (II) a new method were suggested by J. Máleket al.. The results obtained using two types of methods were compared, and it emerged that the results of method II were much more meaningful and reasonable in this work. Additionally, the effects of the molecular structure of the ligands on the kinetic data and models were studied and are discussed.
Summary
A simple and sensitive method of high-performance liquid chromatography with fluorescence detection (HPLC-FLD) was developed for the determination of icariin in capsules by precolumn chelation with aluminum. In order to obtain a stable fluorescence signal, the reaction conditions of the fluorescent chelation complex between icariin and aluminum were investigated in detail. Chromatography was carried out on an Agilent Zorbax Extend C18 column (150 mm × 4.6 mm, 5.0 μm) using methanol as mobile phase at a flow rate of 1.0 mL min−1. The excitation and emission wavelengths were set at 430 and 480 nm, respectively. At optimum conditions, the calibration curve was linear in the concentration range from 0.010 to 100.0 μg mL−1 with the limit of detection of 3.5 ng mL−1 (S/N = 3). A comprehensive method was validated for precision and accuracy. The method described here has been successfully applied for the determination of the icariin content in a capsule with satisfactory results.
Abstract
Solvent extraction of uranyl nitrate in nitric acid medium with the binary system of DMHMP and DOSO has been investigated. It was found that synergistic effect occurs during the extraction of uranyl nitrate with benzene solution of DMHMP and DOSO, the binary species extracted UO2 (NO3)2·DMHMP·DOSO has been confirmed. From the data the equilibrium constants have been determined.
This study is to explore the effect of ALAD polymorphism on hematopoietic, hepatic and renal toxicity from lead in occupational exposure workers
Abstract
Two series of antibacterial compounds were synthesized using montmorillonite and chlorhexidine acetate (CA) by ion-exchange reaction. The resulting samples were characterized by high-resolution thermogravimetric analysis (HRTG), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and their antibacterial activity was assayed by halo method. In this study, the loaded amounts of CA in the resultant compounds were evaluated by the HRTG curves. CA adopts a lateral monolayer arrangement in the resulting samples with low CA loading, while a special state with partial overlapping of organic molecules is supposed for the resulting samples prepared at 1.0–4.0 CEC. After the intercalation with CA, the hydrophilic surfaces of montmorillonite are changed to hydrophobic ones, reflected by the frequency shift of the symmetric ν1(O-H) stretching vibration from low to high. This study shows that the interlayer cations in raw montmorillonite have little influence on the structure of the resulting samples. Antibacterial activity test against E. coli demonstrates that the antibacterial activity of the resulting samples strongly depends on the content of the loaded CA and these resulting materials show a long-term antibacterial activity that can last for at least one year.
Abstract
The present study explores the feasibility of the determination of phosphorus at the extreme trace levels in high-purity silicon by radioreagent method. After silicon dissolution with hydrofluoric and nitric acids and matrix volatilization, 12-molybdophosphoric acid (12-MPA) is formed by the addition of the radioreagent,99MoO 4 2– , in nitric acid medium and then extracted into isobutyl acetate. By plotting the phosphorus content against the radioactivity of99Mo in the organic phase, a linear relationship persisting down to 5 ng is obtained. Special effort has been made to the elimination of the unreacted99MoO 4 2– reagent and the optimal control of phosphorus blank introduced through the multistage analytical procedure in order to ensure reliable determination of phosphorus at the ppb level.
