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111.
Traceability of the measurement of analytical parameters capable of evaluating the performance of methods is an important
concept for the assessment of quality for the routine control, especially for residue monitoring of non-authorized medicinal
substances in food from animal origin. The European Decision no. 657/2002/EC recommends to calculate two statistical limits,
CCα and CCβ, which allow to evaluate the critical concentrations above which the method reliably distinguish and quantify
a substance taking into account the variability of the method and the statistical risk to take a wrong decision. The calculation,
which can be derived from the ISO standard no. 11843 is applied on a routine basis. An example displays a very simple way
for evaluating the performance of an LC-MSMS method which has been validated a few years ago and is qualified onto a Micromass
Quattro LCZ tandem mass spectrometer to monitor and confirm the nitrofuran metabolite residues in food from animal origin.
Community Reference Laboratory for Antimicrobial Veterinary Drug Residue Control in Food from Animal Origin 相似文献
112.
Shlomo Havlin James E. Kiefer George H. Weiss Daniel Benavraham Yehoshua Glazer 《Journal of statistical physics》1985,41(3-4):489-496
We discuss and analyze a family of trees grown on a Cayley tree, that allows for a variable exponent in the expression for the mass as a function of chemical distance, M(l)l
dl
. For the suggested model, the corresponding exponent for the mass of the skeleton,d
l
s
, can be expressed in terms ofd
l
asd
l
s
= 1,d
l
d
l
c
= 2;d
l
s
= d
l
–1,d
1
d
l
c
= 2, which implies that the tree is finitely ramified ford
l
2 and infinitely ramified whend
l
2. Our results are derived using a recursion relation that takes advantage of the one-dimensional nature of the problem. We also present results for the diffusion exponents and probability of return to the origin of a random walk on these trees. 相似文献
113.
G. Tamai H. Yoshida H. Imai T. Takashina K. Kotoo T. Fuwa Y. Tsuchioka H. Matsuura G. Kajiyama 《Chromatographia》1985,20(11):671-676
Summary New quinidine metabolites, including 10,11-dihydrodiol quinidine N-oxide, 10,11-dihydrodiol quinidine and their glucuronides, were found in human urine. A quinidine monitoring HPLC method including these metabolites, is proposed by the direct injection of body fluid samples onto the precolumn for deproteinization followed by reverse phase separation in the analytical column with a column switching technique. The recovery of spiked quinidine and its metabolites in plasma was quantitative (98–102%) with good reproducibility (C.V.: 1.6–4.0%). Several clinical samples such as whole blood and urine were analyzed by the present method. 相似文献
114.
以在低温下(<100℃)实现含羧基/环氧树脂的丙烯酸酯共聚物乳液的交联固化为目的,进行了分子设计;估算了共聚物的组成,用碱滴定法测定了乳胶粒表面的羧基数,并比较了不同单体配比所得乳液的成膜性能. 相似文献
115.
Summary A new gas chromatographic method for the simultaneous determination of the degree of hydrogenation of ketopantolactone and the enantiomeric excess of pantolactone does not require any derivatisation.
Bestimmung von Enantiomerenüberschuß und Hydriergrad bei der enantioselektiven Hydrierung von Ketopantolacton (Kurze Mitt.)
Zusammenfassung Zur Bestimmung des Hydriergrads von Ketopantolacton und des Enantiomerenüberschusses von Pantolacton wird ein neues gaschromatographisches Verfahren eingesetzt, das keine Derivatisierung erfordert.相似文献
116.
Situated in the Taihu plain between the mouth of the Changjiang River and theHangzhou Bay, the Taihu Lake is a large shallow-water lake in China with a surface area of 2427.8 km~2.The lake bottom mainly consists of loess-like sediment. Some buried and silted up channels and residual depressions can be found at the bottom and a lot of Neolithic cultural relics on the loess-like sediment. This indicated that the Taihu Lake was formed on the alluvial plain charaterized by widely deposited loess-like sediment because of siltation and stagnancy of water, instead of by development from lagoons as reported in the past.Recent deposition including influent-effluent current accumulation, wind-driven current and storm deposition in this lake occurred mainly in the south, the west shore and the midst of the lake.The sedimentary rate in the east Taihu Lake is about 1.7-1.8 mm/a, whereas in the west Taihu Lake it is about 0.41 ram/a, only 23% of that of the former. 相似文献
117.
The boundary effect on the drag on two identical, nonuniformly structured flocs moving along the axis of a cylindrical tube
filled with a Newtonian fluid is investigated at a small to medium larger Reynolds number. A two-layer model is adopted to
simulate various possible structures of a floc, and the flow field inside is described by Darcy–Brinkman model. The results
of numerical simulation reveal that a convective flow is present in the rear region of a floc when Reynolds number is on the
order of 40. The presence of the tube wall and/or the porous structure of a floc has the effect of reducing that convective
flow. For a fixed level of the volume-average permeability of a floc, the influence of the tube wall on the drag depends upon
floc structure; the influence on a nonuniformly structured floc is more significant than that on a uniformly structured floc.
The more nonuniform the floc structure, the more appreciable the deviation of the drag coefficient–Reynolds number curve from
a Stokes’-law-like relation becomes. The smaller the volume-average permeability of a floc and/or the smaller the separation
distance between the two flocs, the greater is the deviation, but the presence of the tube wall has the effect of reducing
that deviation. 相似文献
118.
The temperature calibration on cooling of thermal analysis instruments is important for the accurate study of the non-isothermal crystallization kinetics of semi-crystalline polymers. In previous works, a methodology was proposed for performing the calibration on cooling of differential scanning calorimeters (DSCs) with standard metals, and the calibration errors were checked using transitions of high-purity liquid crystals. In this work, alternative, physically meaningful, procedures for carrying out the calibration on cooling are analyzed and validated. The calibration errors are evaluated also with liquid crystalline transitions, when the calibration is performed with standard metals, in a wide temperature range, and when due account is taken for the need of isothermal corrections to the temperature measurements. It is shown that any pair of standard metals may be used to calibrate on cooling, that the calibration errors increase for wider working temperature ranges and that, providing that certain conditions are fulfilled, both calibration procedures yield similar results. 相似文献
119.
Alessandro?De?Robertis Concetta?De?Stefano Demetrio?Milea Silvio?SammartanoEmail author 《Journal of solution chemistry》2005,34(10):1211-1226
Complex formation constants were determined potentiometrically (by a ISE-H+, glass electrode) in the systems, M2+ – Lz – H+ [M2+ = (C2H5)2Sn2+, Lz = malonate, glycinate and ethylenediamine] at t = 25 ∘C and 0.1 mol-L−1≤ I/ ≤ 1 mol-L−1 in NaClaq (0.1 mol-L−1 ≤ I ≤ 0.75 mol-L−1 for the ethylenediamine system). Thermodynamic values of formation constants, at infinite dilution, are [± 95% confidence
interval, Tβpqr refer to the equilibrium, pM2+ + qLz + rH+ = MpLqHr(2+z+r)]: for malonate, log10 Tβ110 = (5.47 ± 0.10); for glycinate, log10 Tβ110 = (9.54 ± 0.08), log10 Tβ111 = (12.97 ± 0.10); and for ethylenediamine, log10 Tβ110 = (10.47 ± 0.10), log10 Tβ120 = (16.17 ± 0.12) and log10 Tβ111 = (15.46 ± 0.10). The dependence on ionic strength of the formation constants was modeled by a simple Debye–Hückel type equation
and by the SIT approach. By analyzing the stability of the species in the three different systems we found a simple additivity
rule that can be expressed by the relationship: log10 K = 6.46 nN + 3.96 nO − 0.60 (nN2+ nO2), with a mean deviation, ε(log10 K) = 0.15 (K = equilibrium constant for the interaction of the organometal cation with the unprotonated or protonated ligand, nN = number of amino groups and nO = number of carboxylic groups of the ligand(s) involved in the formation reaction of complex species). 相似文献
120.