排序方式: 共有121条查询结果,搜索用时 265 毫秒
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Technology and applications of protein microarrays 总被引:2,自引:0,他引:2
Analytical and Bioanalytical Chemistry - 相似文献
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S. Apfalter R. Krska T. Linsinger A. Oberhauser W. Kandler M. Grasserbauer 《Fresenius' Journal of Analytical Chemistry》1999,364(7):660-665
Sixty laboratories of five different countries participated in a large-scale interlaboratory comparison test for the determination
of halogenated hydrocarbons in water. Participants used their in-house method with 44 laboratories applying head space GC
ECD analysis and 5 using liquid/liquid extraction. A set of two artificially produced samples was prepared; the halogenated
hydrocarbons investigated were trichloroethylene, tetrachloroethylene, 1,1,1-trichloroethane, trichloromethane, tetrachloromethane,
1,1-dichloroethylene, dichloromethane, dibromochloromethane, bromodichloromethane, 1,2-dichloroethane and tribromomethane.
The procedure of sample preparation, storage and distribution was monitored by an extensive quality assurance system including
homogeneity tests, stability tests, and trend analysis of the submitted data. The analytical results submitted by the participants
exhibited RSD values of up to 35% and outlier rates of up to 19%. The percentage of false positive and false negative results
was at the highest 12% for selected substances. Recovery rates varying from 86% to 106% proved the correctness of the analytical
results submitted by the participants and showed that the procedure developed in this study for sample preparation and distribution
is well suited for the performance of large-scale interlaboratory comparison tests of halogenated hydrocarbons in water.
Received: 7 December 1998 / Revised: 23 March 1999 / Accepted: 24 March 1999 相似文献
15.
Thomas Peter Josef Linsinger Wolfgang Kandler R. Krska Manfred Grasserbauer 《Accreditation and quality assurance》1998,3(8):322-327
The influence of different evaluation techniques on the results of an interlaboratory comparison for the determination of nutrients in ground- and surface water was investigated. The outlier-test procedure was found to influence the interlaboratory standard deviations (SDs), but not the averages. It was shown that even small differences in the numbers of outliers detected can change the SD severely. Comparing the outlier-test procedures of Hampel, Grubbs and Graf-Henning, it was found that Hampel's test detected the most outliers, thus generally resulting in smaller SDs between interlaboratory comparisons. The Graf-Henning test detected the fewest outliers and its application resulted in the highest SDs of the three test procedures investigated. The comparison of different summarising indices, namely the rescaled sum of z-scores, average of absolute z-scores and average deviation showed no comparability. Possibilities to improve the comparability of interlaboratory comparisons and to minimise misunderstandings are suggested. 相似文献
16.
Strotman NA Baxter CA Brands KM Cleator E Krska SW Reamer RA Wallace DJ Wright TJ 《Journal of the American Chemical Society》2011,133(21):8362-8371
The first example of an intramolecular asymmetric reductive amination of a dialkyl ketone with an aliphatic amine has been developed for the synthesis of Suvorexant (MK-4305), a potent dual Orexin antagonist under development for the treatment of sleep disorders. This challenging transformation is mediated by a novel Ru-based transfer hydrogenation catalyst that provides the desired diazepane ring in 97% yield and 94.5% ee. Mechanistic studies have revealed that CO(2), produced as a necessary byproduct of this transfer hydrogenation reaction, has pronounced effects on the efficiency of the Ru catalyst, the form of the amine product, and the kinetics of the transformation. A simple kinetic model explains how product inhibition by CO(2) leads to overall first-order kinetics, but yields an apparent zero-order dependence on initial substrate concentration. The deleterious effects of CO(2) on reaction rates and product isolation can be overcome by purging CO(2) from the system. Moreover, the rate of ketone hydrogenation can be greatly accelerated by purging of CO(2) or trapping with nucleophilic secondary amines. 相似文献
17.
Krska R Schubert-Ullrich P Josephs RD Emteborg H Buttinger G Pettersson H van Egmond HP Schothorst RC Macdonald S Chan D 《Analytical and bioanalytical chemistry》2007,388(5-6):1215-1226
This paper presents results from the European Commission-funded project Doncalibrant, the objective of which was to produce
calibrators with certified mass fractions of the Fusarium toxins deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-Ac-DON), 15-acetyldeoxynivalenol (15-Ac-DON), and nivalenol (NIV),
in acetonitrile. The calibrators, available in ampoules, were sufficiently homogeneous, with between-bottle variations (s
bb) of less than 2%. Long-term stability studies performed at four different temperatures between −18 and 40 °C revealed no
significant negative trends (at a confidence level of 95%). Molar absorptivity coefficients (in L mol−1 cm−1) were determined for all four toxins (DON: 6805 ± 126, NIV: 6955 ± 205, 3-Ac-DON: 6983 ± 141, 15-Ac-DON: 6935 ± 142) on the
basis of a mini-interlaboratory exercise. The overall uncertainty of the calibrators’ target values for DON and NIV were evaluated
on the basis of gravimetric preparation data and include uncertainty contributions from possible heterogeneity, storage, and
transport. The Doncalibrant project resulted in the production of calibrators for DON (IRMM-315) and NIV (IRMM-316) in acetonitrile
with certified mass fractions of 25.1 ± 1.2 μg g−1 and 24.0 ± 1.1 μg g−1, respectively. Both CRMs became commercially available from the Institute for Reference Materials and Measurements (IRMM,
Geel, Belgium) at the beginning of 2007. 相似文献
18.
R. D. Josephs R. Krska R. Schuhmacher M. Grasserbauer 《Analytical and bioanalytical chemistry》1999,363(1):130-131
The development of a rapid method for the determination of the Fusarium mycotoxin beauvericin (BEA) in corn and cereals is described. This method allows to prepare at least 5 times more samples simultaneously with similar analytical performance characteristics as previously published analytical methods. 相似文献
19.
S. Apfalter R. Krska T. Linsinger A. Oberhauser W. Kandler M. Grasserbauer 《Analytical and bioanalytical chemistry》1999,364(7):660-665
Sixty laboratories of five different countries participated in a large-scale interlaboratory comparison test for the determination of halogenated hydrocarbons in water. Participants used their in-house method with 44 laboratories applying head space GC ECD analysis and 5 using liquid/liquid extraction. A set of two artificially produced samples was prepared; the halogenated hydrocarbons investigated were trichloroethylene, tetrachloroethylene, 1,1,1-trichloroethane, trichloromethane, tetrachloromethane, 1,1-dichloroethylene, dichloromethane, dibromochloromethane, bromodichloromethane, 1,2-dichloroethane and tribromomethane. The procedure of sample preparation, storage and distribution was monitored by an extensive quality assurance system including homogeneity tests, stability tests, and trend analysis of the submitted data. The analytical results submitted by the participants exhibited RSD values of up to 35% and outlier rates of up to 19%. The percentage of false positive and false negative results was at the highest 12% for selected substances. Recovery rates varying from 86% to 106% proved the correctness of the analytical results submitted by the participants and showed that the procedure developed in this study for sample preparation and distribution is well suited for the performance of large-scale interlaboratory comparison tests of halogenated hydrocarbons in water. 相似文献
20.
Rapid test strips for analysis of mycotoxins in food and feed 总被引:2,自引:0,他引:2
An overview is given on recent trends and applications of rapid immunodiagnostic tests for screening of food and feed for
mycotoxins. Different test formats are discussed, and challenges in the development of lateral-flow devices for on-site determination
of mycotoxins, with requirements such as being robust, fast, and cost-effective, are briefly elucidated. 相似文献