A liquid chromatographic tandem mass spectrometric (LC–MS–MS) method for the determination of five chemical coccidiostats (decoquinate, diclazuril, halofuginone, nicarbazin, and robenidine) and five ionophore coccidiostats (maduramicin, monensin, narasin, salinomycin, and semduramicin) in yoghurt, kefir, and sour cream is presented. Lasalocid, the sixth ionophore listed in 124/2009/EC was not included because of its extremely dissimilar behavior during sample preparation. Main steps of the method include extraction with acetonitrile, centrifugation, clean-up on Oasis HLB solid phase extraction cartridge, evaporation under nitrogen stream, and LC–MS–MS determination. Selectivity, linearity, sensitivity, accuracy, repeatability, within-laboratory reproducibility, limit of determination, and limit of quantitation were determined during the validation procedure. The method proved to be applicable for both qualitative and quantitative determination of the ten above-mentioned target compounds. In our in-house fermentation experiments, milk fortified with coccidiostats was fermented to get yoghurt, kefir, and sour cream. Our results show that the coccidiostat content did not change significantly during fermentation for any of the target compounds.
We study existence of a unique mild solution of evolution quantum stochastic differential equations with nonlocal conditions under the strong topology. Using the method of successive approximations, we do not need to transform the nonlocal problem to a fixed point form. The evolution operator A generates a family of semigroup that are continuous. Nonlocal conditions allow additional measurements of certain phenomena that cannot be captured by the traditional initial conditions. We show that under some given conditions, the mild solution is unique and also stable. The method applied here is much easier when compared with previous methods used in literature. 相似文献
The reaction of stoichiometric MeLi with the 1:1 mixture of (?5‐C5H5)Fe(CO)2I/P(OR)3 (R = Me, Et, and Ph) at ?78°C changes the bonding mode between metal and ring from (?5‐C5H5) to (?4‐exo‐MeC5H5) and the oxidation state of metal from Fe(II) to Fe(O), the novel complexes (?4‐exo‐MeC5H5)Fe(CO)2P(C)R)3 being obtained in 45‐57% yields. The reaction of trace MeLi with the 1:1 mixture of (?5‐C5H5)Fe(CO)2I/P(OMe)3 at ?78°C results in 70% yield of the phosphonate complex (?5‐C5H5)Fe(CO)2P(O)(OMe)2 which is an Arbuzov‐like dealkylation product from the cationic intermediate [(?5‐C5H5)Fe(CO)2P(OMe)3+] and the iodide. The amines could assist the Arbuzov‐like dealkylation of [(?5‐C5H5)Fe(CO)2P(OMe)3+] [PF6?] where iron‐carbamoyl intermediates are likely involved in the case of primary amines. 相似文献
The paper describes the applicability of different characteristics (signatures) in nuclear safeguards and forensics for assessment of uranium material provenance in terms of production process. The study follows a uranium ore concentrate production from an ore to a U3O8 product. It turned out that rare-earth elemental pattern, radiochronometry (age of ore body and material production date), sulphur and organic impurities are useful to find out the origin or history of the material, while certain trace-elements and isotopics of Pb or Sr were found to be inconclusive. The results will be important to understand the signatures in nuclear safeguards and forensics. 相似文献
New ruthenium(II) complexes containing labile nitrile ligands have been prepared by treatment of either the polymer [{RuCl2(COD)}x] (COD = cycloocta-1,5-diene) (1) or its derivative [RuCl2(COD)(NCCH3)2]·NCCH3 (2) with the appropriate nitrile ligands in refluxing acetonitrile under argon. A new route to synthesis of trans-dichlorotetrakis(diphenylphosphine)ruthenium(II) (7) was also reported. A redetermination of the structure of 7 was undertaken and X-ray crystallographic data revealed that the complex crystallizes in the triclinic space group P-1 with unit cell dimensions a = 12.7016(9) Å, b = 13.0847(10) Å, c = 14.1498(10) Å, α = 101.46(3)°, V = 2080.6(3) Å3, Z = 2 and R = 0.0309. Its polymorph 7′ was also obtained. The crystal structure of 4 was also determined. This complex crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 27.0510(3) Å, b = 11.0984(13) Å, c = 13.0450(16) Å, α = 90°, V = 3886.5(8) Å3, Z = 8 and R = 0.0282. 相似文献
In our study we have identified phase I metabolites of cardiovascular and anti-ulcer agents with the application of predictive multiple reaction monitoring (pMRM) methods with liquid-chromatography-triple-quadrupole mass spectrometry (LC-QQQ-MS) in surface water samples. Targeted accurate mass spectrometry measurements were also carried out for confirmation with liquid-chromatography-time-of-flight mass spectrometry (LC-TOF-MS). pMRM followed by a targeted accurate mass spectrometry measurement can provide a sound basis for the selection of metabolites to be included in analytical methods for the investigation of environmental load of pharmaceuticals. Using LC-QQQ-MS twenty-one metabolites could be identified with two independent transitions at the same retention time and six of them could also be confirmed with LC-TOF-MS. 相似文献
In this paper, we attempt to determine the self-attenuation correction factor for 37 different sand samples collected from Antalya region of Turkey with densities changing from 2.205 to 2.679 g \(\hbox {cm}^{-3}.\)Transmission method has been used in order to obtain self-attenuation correction factor in comparison with the air and ultrapure water samples for each case. Self-attenuation correction factor versus energy fit curve is obtained. While the self-attenuation correction factor has large values at low energies, it becomes smaller at high energies and tends to become constant thereafter. 相似文献