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141.
Both the Kjeldahl and the Dumas methods for the determination of protein in foodstuffs are currently in use, but the empirical nitrogen factors used to convert the determined nitrogen content to protein content are based on the Kjeldahl method alone. Non-equivalence between the two methods could therefore result in some laboratories reporting an incorrect protein content. We report here a study using data accumulated over several years in the results of a proficiency testing scheme. On average the Dumas method provided results that were relatively higher by about 1.4% than the Kjeldahl method, but the difference between the methods depended on the type of foodstuff. The methodology of looking for bias between analytical methods is critically discussed. 相似文献
142.
J. F. Bergmann L. Rosenthaler J. A. Wilkinson I. R. Sipherd E. I. Fulmer L. M. Christensen E. R. Caley A. K. Anderson A. H. Rouse Th. V. Letonoff J. H. Fenton O. L. Osburn H. G. Wood C. H. Werkmau und J. Doeuvre 《Fresenius' Journal of Analytical Chemistry》1936,106(7-8):304-311
Ohne Zusammenfassung 相似文献
143.
144.
Rapid cloning and expression of a fungal polyketide synthase gene involved in squalestatin biosynthesis 总被引:7,自引:0,他引:7
Cox RJ Glod F Hurley D Lazarus CM Nicholson TP Rudd BA Simpson TJ Wilkinson B Zhang Y 《Chemical communications (Cambridge, England)》2004,(20):2260-2261
PCR primers designed to selectively amplify the unique C-methyltransferase domain of fungal polyketide synthases were used to selectively clone a polyketide synthase gene involved in the biosynthesis of the squalene synthase inhibitor squalestatin S1 , heterologous expression of which led to the biosynthesis of the squalestatin side-chain. 相似文献
145.
A multiresidue supercritical fluid extraction procedure for chlorinated dibenzofurans (PCDFs) has been optimized as an efficient method for the determination of these compounds in fly ash samples. The results were compared with those obtained by Soxhlet extraction. Extracts from the two procedures were analyzed by gas chromatography–mass spectrometry (HRGC–MS) Statistical analysis of the results confirmed that supercritical fluid extraction provides data with a relative standard deviation of less than 10% while Soxhlet extraction data show a much greater spread. 相似文献
146.
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148.
A. H. Jay W. W. Stevenson E. W. Colbeck S. W. Craven W. Murray N. T. Wilkinson W. J. Agnew R. Treje C. Benedicks G. A. Medwedewa W. P. Remin F. Willems J. J. Berzelius Ed. Houdremont P. Klinger G. Blaschczyk P. Klineer und W. Koch 《Fresenius' Journal of Analytical Chemistry》1944,127(1):43-46
Ohne Zusammenfassung 相似文献
149.
Wilkinson I Garcia IA Whitaker BJ Hamard JB Blanchet V 《Physical chemistry chemical physics : PCCP》2010,12(48):15766-15779
We present velocity map images of the NO, O((3)P(J)) and O((1)S(0)) photofragments from NO(2) excited in the range 7.6 to 9.0 eV. The molecule was initially pumped with a visible photon between 2.82-2.95 eV (440-420 nm), below the first dissociation threshold. A second ultraviolet laser with photon energies between 4.77 and 6.05 eV (260-205 nm) was used to pump high-lying excited states of neutral NO(2) and/or probe neutral photoproducts. Analysis of the kinetic energy release spectra revealed that the NO photofragments were predominantly formed in their ground electronic state with little kinetic energy. The O((3)P(J)) and O((1)S(0)) kinetic energy distributions were also dominated by kinetically 'cold' fragments. We discuss the possible excitation schemes and conclude that the unstable photoexcited states probed in the experiment were Rydberg states coupled to dissociative valence states. We compare our results with recent time-resolved studies using similar excitation and probe photon energies. 相似文献
150.
Air-trapping on biocompatible nanopatterns 总被引:1,自引:0,他引:1
Martines E Seunarine K Morgan H Gadegaard N Wilkinson CD Riehle MO 《Langmuir : the ACS journal of surfaces and colloids》2006,22(26):11230-11233
The occurrence of air-trapping inside poly-eta-caprolactone nanopits was investigated by measuring the contact angles of water droplets on a set of defined nanotopographies. It is shown that the advancing angles follow the Cassie-Baxter theory, thus revealing the presence of air bubbles inside the biodegradable nanopatterns. The importance of these observations for the definition of hydrophilicity/hydrophobicity and in the context of in vitro cell behavior is discussed. 相似文献