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61.
Storr T Obata M Fisher CL Bayly SR Green DE Brudziñska I Mikata Y Patrick BO Adam MJ Yano S Orvig C 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,11(1):195-203
Seven discrete sugar-pendant diamines were complexed to the {M(CO)(3)}(+) ((99m)Tc/Re) core: 1,3-diamino-2-propyl beta-D-glucopyranoside (L(1)), 1,3-diamino-2-propyl beta-D-xylopyranoside (L(2)), 1,3-diamino-2-propyl alpha-D-mannopyranoside (L(3)), 1,3-diamino-2-propyl alpha-D-galactopyranoside (L(4)), 1,3-diamino-2-propyl beta-D-galactopyranoside (L(5)), 1,3-diamino-2-propyl beta-(alpha-D-glucopyranosyl-(1,4)-D-glucopyranoside) (L(6)), and bis(aminomethyl)bis[(beta-D-glucopyranosyloxy)methyl]methane (L(7)). The Re complexes [Re(L(1)-L(7))(Br)(CO)(3)] were characterized by (1)H and (13)C 1D/2D NMR spectroscopy which confirmed the pendant nature of the carbohydrate moieties in solution. Additional characterization was provided by IR spectroscopy, elemental analysis, and mass spectrometry. Two analogues, [Re(L(2))(CO)(3)Br] and [Re(L(3))(CO)(3)Br], were characterized in the solid state by X-ray crystallography and represent the first reported structures of Re organometallic carbohydrate compounds. Conductivity measurements in H(2)O established that the complexes exist as [Re(L(1)-L(7))(H(2)O)(CO)(3)]Br in aqueous conditions. Radiolabelling of L(1)-L(7) with [(99m)Tc(H(2)O)(3)(CO)(3)](+) afforded in high yield compounds of identical character to the Re analogues. The radiolabelled compounds were determined to exhibit high in vitro stability towards ligand exchange in the presence of an excess of either cysteine or histidine over a 24 h period. 相似文献
62.
Joanna Szpunar-Łobińska Michiel Ceulemans Wilfried Dirkx Claudia Witte Ryszard Łobiński Freddy C. Adams 《Mikrochimica acta》1994,113(3-6):287-298
Interferences in trace and ultratrace speciation analysis of organotin and organolead compounds in various samples by gas chromatography coupled with atomic absorption spectrometry (AAS) and/or microwave induced plasma atomic emission spectrometry (MIP AES) are investigated. Particular attention is given to the effects of matrix co-extractives and reagents impurities introduced during sample preparation. Their influence on the detection limits is discussed in terms of baseline noise level, blank value, formation of artefacts and signal suppression. Loss of column resolution during the analysis of some matrices is observed. 相似文献
63.
Elhottová D Tríska J Petersen SO Santrůcková H 《Fresenius' Journal of Analytical Chemistry》2000,367(2):157-164
Application of gas chromatography-mass spectrometry (GC-MS) can significantly improve trace analyses of compounds in complex matrices from natural environments compared to gas chromatography only. A GC-MS/MS technique for determination of poly-beta-hydroxybutyrate (PHB), a bacterial storage compound, has been developed and used for analysis of two soils stored for up to 319 d, fresh samples of sewage sludge, as well as a pure culture of Bacillus megaterium. Specific derivatization of beta-hydroxybutyrate (3-OH C4:0) PHB monomer units by N-tert-butyl-dimethylsilyl-N-methyltrifluoracetamide (MTBSTFA) improved chromatographic and mass spectrometric properties of the analyte. The diagnostic fragmentation scheme of the derivates tert-butyldimethylsilyl ester and ether of beta-hydroxybutyric acid (MTBSTFA-HB) essential for the PHB identification was shown. The ion trap MS was used, therefore the scan gave the best sensitivity and with MS/MS the noise decreased, so the S/N was better and also with second fragmentation the amount of ions increased compared to SIM. The detection limit for MTBSTFA-HB by GC-MS/MS was about 10(-13) g microL(-1) of injected volume, while by GC (FID) and GC-MS (scan) it was around 10(-10) g microL(-1) of injected volume. Sensitivity of GC-MS/MS measurements of PHB in arable soil and activated sludge samples was down to 10 pg of PHB g(-1) dry matter. Comparison of MTBSTFA-HB detection in natural soil sample by GC (FID), GC-MS (scan) and by GC-MS/MS demonstrated potentials and limitations of the individual measurement techniques. 相似文献
64.
B. Skwarzec D. I. Strumińska A. Boryło J. Falandysz 《Journal of Radioanalytical and Nuclear Chemistry》2004,261(3):661-663
238U, 234U and 210Po activity concentrations were determined in beer in Poland by alpha-spectrometry with low-level activity silicon detectors.
The results revealed that the mean concentrations of 238U, 234U and 210Po in the analyzed beer samples were 4.63, 4.11 and 4.94 mBq·dm−3, respectively, the highest in Tyskie (5.71 for 210Po, 5.06 for 234U and 6.11 for 238U) and the lowest in Lech (2.49 for 210Po). The effective radiation dose due to uranium and polonium ingestions by beer was calculated and were compared to the effective
radiation dose from drinking water.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
65.
Maria Bocheska Maria Hoffmann Urszula Lesiska Emilia Luks Wanda Radecka-Paryzek 《Tetrahedron》2005,61(52):12307-12313
New compounds: 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis(3-diisopropoxyphosphorylpropoxy)calix[4]arene (1) and 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis(3-methoxyethoxyphosphorylpropoxy)calix[4]arene (2) were synthesized and their ionophoric properties in ion-selective membrane electrodes were studied in comparison with already described by us 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis(3-diethoxyphophorylpropoxy)calix[4]arene (3). Complexes of 1 with calcium(II), lanthanum(III), europium(III) and gadolinium(III) nitrates were prepared in direct reaction of the ligand and appropriate metal salts. They were characterized by spectral data (IR, UV/Vis, luminescence, NMR, ESI-MS) and elemental analysis. The similarity in complexing behavior of the (dialkoxyphosphoryl)propoxy-calix[4]arenes toward calcium and some lanthanides was observed. 相似文献
66.
Wojciech Duczmal Beata Maciejewska Elżbieta Śliwińska Bogdan Marciniec 《Transition Metal Chemistry》1995,20(2):162-165
Summary Trisubstituted silanes, HSiR3–n
X
n
(R = Me, Et, Pr or Bu; X = Cl, OEt or Ph; and n = 0–3) readily undergo oxidative addition to complex [RhCl(cod)PPh3] (where cod = cycloocta-1,5-diene).The quantitative correlation between rate constants, k
1, of the reaction, followed spectrophotometrically at 20 °C in benzene solutions, and the structure of tri-substituted silanes represented by stereoelectronic parameters , and E of the substituents, was established: logk
1 = a + b + c + dE. The reaction rate is accelerated by electron-withdrawing substituents at silicon and retarded by the bulk and pd donation of nonalkyl substituents.Author to whom all correspondence should be directed. 相似文献
67.
Chemical modification of nonionic sorbent Amberlite XAD-2 or anion exchanger Amberlyst A-26 with Eriochrome Blue-Black R (EBBR) produces a chelating resin of satisfactory chemical stability and resistance towards mineral acids. Retention of 10 metal ions has been examined for both resins. EBBR loaded XAD-2 was utilized for nickel(II) preconcentration in atomic-absorption spectrometry. In optimal conditions at a preconcentration time not exceeding 1 hr, nickel(II) can be determined at the 0.1 mug/l. level in flow measurements. Retention of metal ions on chelating resin is a convenient method of preconcentration and elimination of matrix interferences. 相似文献
68.
H. Jaskólska L. Rowińska M. Radwan 《Journal of Radioanalytical and Nuclear Chemistry》1974,20(2):419-428
In view of the inhomogeneous distribution of lanthanum in steel, large samples should be used for the determination of this element. The method elaborated consists in the preparation of an average samople by dissolving 50 g steel and analysing an aliquot of the obtained solution corresponding to 0.5 g of steel. In order to reduce the activity of the sample, iron and some other elements are separated from the steel solution by electrolysis prior to irradiation. The amount of lanthanum contamination introduced during the pre-irradiation treatment of the sample is relatively low (10?10–10?9 g) if the treatment is carried out under suitable conditions. The post-irradiation treatment consists in the separation of24Na by shaking the sample solution with Sb2O5. The140La-activity is measured by means of a γ-spectrometer (1.6 MeV photopeak). 相似文献
69.
Maria Bocheńska Jan F. Biernat 《Journal of inclusion phenomena and macrocyclic chemistry》1993,16(1):63-68
New compounds — podands and cryptands with two secondary sulfonamide groups —have been synthesized and are described. They were tested as ionophores for guanidinium ions in PVC-membrane electrodes with bis (2-ethylhexyl)sebacate (DOS) as plasticizer. 相似文献
70.
J. Legendziewicz K. Bukietyńska G. Oczko S. Ernst B. Jeżowska-Trzebiatowska 《Chemical physics letters》1980,73(3):576-581
Absorption spectra of holmium nitrate in MFA and DMF have been measured in the range 8000–42000 cm?1. The τλ parameters were evaluated from the experimental oscillator strengths using the Judd equation. For Ho(NO3)3 in DMF a considerable increase in τ2 was observed, suggesting the existence of inner-sphere species in this system. This suggestion was verified by ultrasonic absorption and conductivity measurements. 相似文献