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321.
322.
A multiresidue analytical method for the determination of emerging pollutants belonging to personal care products (PCPs) (antimicrobials, preservatives), benzotriazole UV stabilizers (BUVSs) and organophosphorus compounds (OPCs) in fish has been developed using high speed solvent extraction (HSSE) followed by silica gel clean up and ultra fast liquid chromatography coupled with tandem mass spectrometry (UFLC–MS/MS) analysis. Developed extraction and clean up method yielded good recovery (>70%) for all the four groups of emerging pollutants, i.e. antimicrobials (78.5–85.6%), preservatives (85.0–89.4%), BUVSs (70.9–112%) and OPCs (81.6–114%; except for TEP – 68.9% and TPeP – 58.1%) with RSDs ranging from 0.7 to 15.4%. Intra- and inter-day repeatabilities were less than 19.8% and 19.0%, respectively at three spiked levels. The concentrations were given in lipid weight (lw) basis, and the method detection limits were achieved in the lowest range of 0.001–0.006 ng g−1 for two antimicrobials, 0.001–0.015 ng g−1 for four preservatives, 0.0002–0.009 ng g−1 for eight BUVSs and 0.001–0.014 ng g−1 for nine OPCs. Finally, the method was successfully validated as a simple and fast extraction method for the determination of 23 compounds belonging to PCPs, BUVSs and OPCs and applied to the analysis of three species of fish from Manila Bay, the Philippines. Concentrations ranged from 27 to 278 ng g−1 for antimicrobials, 6.61 to 1580 ng g−1 for paraben preservatives, −1 for BUVSs and ND (not detected) to 266 ng g−1 for OPCs suggesting the ubiquitous contamination by these emerging pollutants in Manila Bay. This is the first method developed for the determination of triclocarban, four paraben preservatives and four BUVSs, in fish. 相似文献
323.
Shinsuke Yorozu 《Israel Journal of Mathematics》1986,56(3):349-354
We give a generalization of the result obtained by C. Currás-Bosch. We consider the Av-operator associated to a transverse Killing fieldν on a complete foliated Riemannian manifold (M, ℱ, g). Under a certain assumption, we prove that, for eachx ∈M, (Av)
x
belongs to the Lie algebra of the linear holonomy group ψv(x). A special case of our result, the version of the foliation by points, implies the results given by B. Kostant (compact
case) and C. Currás-Bosch (non-compact case). 相似文献
324.
Eiji Ihara Shinsuke Tanaka Kenzo Inoue 《Journal of polymer science. Part A, Polymer chemistry》2002,40(23):4302-4315
Molybdenum chloride (MoCl5 or 1a ) and tungsten chloride (WCl6 or 1b )/phenyllithium (PhLi)/triisobutylaluminum (iBu3Al) systems were found to be quite effective for controlling the anionic polymerization of methyl methacrylate (MMA), affording high molecular weight poly(methyl methacrylate)s (PMMAs; number‐average molecular weight > 100,000) with narrow molecular weight distributions (weight‐average molecular weight/number‐average molecular weight < 1.25) quantitatively at 0 °C for 1 h in toluene. Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) analyses of PMMAs obtained with the 1a and 1b /organolithium (RM; n‐butyllithium, PhLi)/iBu3Al systems revealed that the initiation of MMA with the systems occurred by a nucleophilic attack of H? to the monomer. In addition, the MALDI‐TOF MS analyses indicated that the presence of iBu3Al was responsible for the controlled polymerization by improving the uniformity of the polymerization with respect to initiation and termination and by preventing a backbiting reaction. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4302–4315, 2002 相似文献
325.
Shuichi Ohuchida Nobuyuki Hamanaka Shinsuke Hashimoto Masaki Hayashi 《Tetrahedron letters》1982,23(28):2883-2886
The synthesis of thromboxane A2 (TXA) analogue, 9α,11α-thia-TXA2 methyl ester , in which the oxygen atom in the oxetane ring of TXA2 was replaced by a sulfur atom, is described. 相似文献
326.
The thermolysis of pivaloyl- and adamantoyltris(trimethylsilyl)germane in the presence of 2,3-dimethyl- and 2,3-diphenyl-1,3-butadiene gave the respective adducts derived from [2+4] cycloaddition of the germenes with butadienes in good yields. 相似文献
327.
Substituent-control exciton in J-aggregates of protonated water-insoluble porphyrins 总被引:2,自引:0,他引:2
A series of protonated porphyrin J-aggregates of various water-insoluble tetraphenylporphyrin derivatives was prepared by aggregation at the liquid-liquid or gas-liquid interface. Using atomic force microscopy, we observed microcrystalline porphyrin J-aggregates. The J-aggregates have two strong exciton bands corresponding to the B (Soret)- and Q-bands of the protonated porphyrin. Interestingly, the excitation energy of the lower exciton (denoted by S1) markedly depends on the meso-substituents, whereas that of the higher exciton (denoted by S2) does not depend on them. These results indicate that the nature of the exciton coupling of the S1 transition dipole moment can be systematically changed by the substituents. 相似文献
328.
Vinay Gupta Tsuyoshi Nakajima Yoshimi Ohzawa Boris
emva 《Journal of fluorine chemistry》2003,120(2):143-150
Raman spectra were measured of highly fluorinated graphite samples prepared at room temperature, 380 and 515 °C. CxF prepared at room temperature showed a novel downshifted band at 1555–1542 cm−1 along with G band at 1593–1583 cm−1. Similar behavior is also observed for samples prepared at 380 and 515 °C at early stages of fluorination, after which the Raman shifts completely disappeared. Raman spectra as well as X-ray diffraction (XRD) analysis suggest that graphite fluorides, (CF)n and (C2F)n are formed via fluorine-intercalated phase with planar graphene layers. 相似文献
329.
Masaru Sato Shinsuke Tanaka Seiji Ebine Kenichi Morinaga Sadatoshi Akabori 《Journal of organometallic chemistry》1985,282(2):247-253
Of the 1,n-dithia[n]ferrocenophanes prepared from disodium 1,1′-ferrocenedithiolate and polymethylene dibromides, the ferrocenophane with n = 7 showed the largest shift in the electronic and 13C NMR spectra and the largest decrease of the redox potential. This can be interpreted by a new type of stereoelectronic interaction between the sulfur atom and the ferrocene nucleus. 相似文献
330.
A photochromic complex with disulfur and dimethyl-ethylene-1,2-dithiolate ligands, [Mo(2)(mu-S(2))(mu-S(2)C(2)Me(2))(2)(S(2)C(2)Me(2))(2)] (3), was synthesized and characterized. Photoirradiation of 3 with visible light resulted in the formation of the isomer (3'). The electronic spectrum of 3' has a new intense peak in the near infrared region, and in the dark, the spectrum returns to that of 3. X-ray structural analyses of 3.C(6)H(6) and 3' revealed a large conformational change of the bridging dithiolate ligands: the two ligands in 3' come very close to each other compared to those in 3.C(6)H(6). Crystal data: 3.C(6)H(6), monoclinic, space group C2/c, a = 15.193(4) A, b = 14.287(3) A, c = 14.685(4) A, beta = 105.30(1) degrees, V = 3074(1) A(3), Z = 4; 3', monoclinic, space group C2/c, a = 21.5400(8) A, b = 9.5232(5) A, c = 13.9828(2) A, beta = 118.924(1) degrees, V = 2510.5(2) A(3), Z = 4. (1)H NMR spectra of 3 (3.06, 3.05, 1.66, and 1.31 ppm) and 3' (2.90, 2.75, 2.14, and 1.97 ppm) are also reported: each spectrum has four signals due to methyl groups, which accords well with the fact that each of the molecules, 3.C(6)H(6) and 3', has a crystallographic 2-fold axis. 相似文献