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861.
J. Hanus L Bellier W. Olszewski Th. Sundberg M. Lundborg L. W. Winkler L. Mascarelli A. Blasi A. Panchaud P. Bohrisch F. Kürschner E. Rupp St. Weiser H. G. Donáth W. Arnold O. Köpke W. Manchot K. W. Rosenmund W. Kuhnhenn W. Vaubel H. P. Kaufmann E. Hansen-Schmidt E. Schulek H. Ingle K. H. Bauer P. Manicke W. Fahrion M. Auerbach S. Fachini R. Ehrenstein P. Griegel Y. Toyama 《Analytical and bioanalytical chemistry》1927,72(4):163-173
862.
Summary A common strategy in the numerical integration over ann-dimensional hypercube or simplex, is to consider a regular subdivision of the integration domain intom
n
subdomains and to approximate the integral over each subdomain by means of a cubature formula. An asymptotic error expansion whenm is derived in case of an integrand with homogeneous boundary singularities. The error expansion also copes with the use of different cubature formulas for the boundary subdomains and for the interior subdomains. 相似文献
863.
864.
Crude palm oil contains 600 to 1000 ppm of tocols in the form of tocopherols and tocotrienols. These palm tocols have been isolated and analyzed in the past by various chromatographic techniques such as open column chromatography, high-performance liquid chromatography, as well as thin-layer chromatography. Supercritical fluid chromatography (SFC) has emerged as a more advanced chromatographic technique in recent years. The tocols present in palm oil are successfully isolated using SFC. Identification of these tocols is supported by various spectroscopic techniques such as 1H NMR, 13C NMR, and mass spectrometry. 相似文献
865.
S. May J. Leroy D. Piccot G. Pinte 《Journal of Radioanalytical and Nuclear Chemistry》1982,72(1-2):305-318
Neutron activation analysis has been used for the determination of trace elements in different wines coming from various french
vineyards. The technics used are non destructive for short and middle half-life radionuclides (28Al−76As−49Ca−38Cl−42K−27Mg−56Mn−24Na−52V). A radiochemical separation is necessary for longer half-life radionuclides (60Co−52Cr−134Cs−59Fe−86Rb−65Zn). The results of our study show that the identification of vineyards based on the determination of specific oligo-elements
can be proposed. However more data are needed to demonstrate that the knowledge of the amounts of specific oligo-elements
in a wine corresponding to a given vineyard can be used for disclose frauds more particularly in the cases of wine watering
or mixtures of wines coming from different vineyards.
相似文献
866.
Several extraction and derivatization procedures were evaluated for the quantification of (2-methoxyethoxy)acetic acid (MEAA)
in urine. MEAA is a metabolite and a biomarker for exposure to 2-(2-methoxyethoxy)ethanol, a glycol ether with widespread
use in various industrial applications and the specific use as an anti-icing additive in the military jet fuel formulation
JP-8. Quantification of glycol ether biomarkers is an active area of analytical research. Various sample preparation procedures
were evaluated: liquid–liquid extraction (LLE) using ethyl acetate yielded the highest recovery, and solid-phase extraction
(SPE) gave low recovery of MEAA. Two derivatization procedures were thoroughly investigated and validated, namely, silylation
of MEAA with N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA), and esterification of MEAA using ethanol. Quantification was performed by
gas chromatography (GC) with a mass spectrometer as detector and using a polydimethylsiloxane (HP-1) capillary column. Deuterated
2-butoxyacetic acid (d-BAA) was used as an internal standard. Recovery studies of spiked human urine demonstrated the accuracy
and precision of both procedures. The limit of detection (LOD) and other figures of merit for both derivatization procedures
will be discussed in detail. Applications of these analysis procedures are also discussed.
Disclaimers Mention of company names and/or products does not constitute endorsement by the Centers for Disease Control and Prevention
(CDC). The findings and conclusions in this report are those of the authors and do not necessarily represent the views of
the National Institute for Occupational Safety and Health. 相似文献
867.
Razak bin Ali Pradyot Banerjee John Burgess Ann E. Smith 《Transition Metal Chemistry》1988,13(2):107-112
Summary The solvatochromic behaviour of W(CO)4(LL), LL=a diazabutadiene or a pyridine Schiff base, and of Mo(CO)4 (butane-2,3-dionedihydrazone) is described. Pressure effects on the charge-transfer spectra of these compounds, the [Mo(CO)4(fz)]2– anion {fz=ferrozine; 3-(2-pyridyl)-5, 6-bis-(4-sulphonatophenyl)-1,2,4-triazine}, and Fe(bipy)2(CN)2 are reported. Solvent sensitivities are discussed in terms of the nature of the ligands and of the central metal atom, and the idea of a correlation between these solvent sensitivities and piezochromic behaviour developed for these and related ternary irondiimine-cyanide species.Author to whom all correspondence should be directed. 相似文献
868.
The VIDAS Immuno-concentration Salmonella (ICS) plus selective plate method (Hektoen enteric, xylose lysine desoxycholate, bismuth sulfite) method for the detection of Salmonella was compared to the Bacteriological Analytical Manual (BAM)/AOAC culture method in a collaborative study. Thirty-two laboratories participated in the evaluation. Each laboratory tested one or more of the 6 test products: milk chocolate, nonfat dry milk, dried whole egg, soy flour, ground black pepper, and ground raw turkey. The 2 methods were in agreement for 1,297 of the 1,455 samples. Of the 158 samples not in agreement, 82 were VIDAS ICS plus selective plate-positive and BAM/AOAC-negative, and 76 were VIDAS ICS plus selective plate-negative and BAM/AOAC-positive. 相似文献
869.
870.
Equilibrium configurations of self-gravitating massless thermal radiation inside spherical boxes of radiusR in asymptotically anti-de Sitter space (A = -3/b
2) are constructed numerically for a range of central densities. For each box radius considered (R/b = 0, 1/2, 1, 2, 4, ), there is a unique configuration with maximal total mass and entropy, and another (at a lower central density) with maximum asymptotic red-shifted temperature. With the box removed toR=, the maximum total mass and entropy of self-gravitating thermal radiation areM
max 0.4598b0.7964(–A)–1/2 andS
max1.3560a
1/4
b
3/2 3.0910a
1/4(–A)–3/4, and the maximum red-shifted temperature is 相似文献