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991.
Leuschner RG Bew J Cruz A Adler A Auclair E Bertin G Braconnier M Domig K Jones P Kneifel W Krause M Marmo S Michard J Mietke H O'Briain A Olofson AS Ruppitsch W Thalmann A Voets A Warmerdam C 《Journal of AOAC International》2003,86(3):568-575
Fourteen out of 17 laboratories completed an interlaboratory study comparing 2 pretreatment protocols of feed samples containing authorized probiotic bacilli spores. Both methods used tryptone soy agar for enumeration. Pretreatment A involved preparation of a suspension of the feed sample in 50% ethanol. For pretreatment B, the sample was suspended in peptone salt solution and heated at 80 degrees C for 10 min. Each laboratory analyzed 12 samples (6 per pretreatment), which represented duplicates of a high (10(9) colony-forming units [CFU]/g) and low (10(5) CFU/g) level of bacilli spores or a blank that contained vegetative probiotic bacteria only. For pretreatment A, the repeatability relative standard deviation (RSD(r)) was 2.9% for the low level and 2.5% for the high. The reproducibility relative standard deviation (RSDR) values were 7.8 and 5.9%, respectively. Pretreatment B revealed RSD(r) values of 1.1 and 1.0%, and RSDR values of 5.8 and 3.4%, respectively. The heat treatment (pretreatment B) of feed samples had better precision data, resulted in higher viable bacilli counts, and was more effective in deactivating vegetative background flora. It is therefore recommended for adoption for official control purposes and for CEN and ISO standards. 相似文献
992.
993.
Contributions on the Thermal Behaviour of Sulfates XII. The Chemical Vapour Transport of In2(SO4)3 with Cl2 and HCl. Experimental Results and Calculations By means of CVT (T1 between 500°C and 825°C; ΔT = 50°C), well shaped crystals of anhydrous In2(SO4)3 can be grown in the less hot region of a closed silica ampoule. We investigated the dependence of the deposition rate on the variation of the concentration of the transport agent (system In2(SO4)3/Cl2) and on the variation of the transport temperature (In2(SO4)3/Cl2 as well as In2(SO4)3/HCl). A comparison of the experimental results with thermodynamical calculations shows a satisfying agreement. The influence of the variation of some additional parameters (H2O from the wall of the ampoule; ΔBH(In2(SO4)3)) on the deposition rate is discussed. 相似文献
994.
Rolf Neeb 《Fresenius' Journal of Analytical Chemistry》1961,179(1):21-29
Zusammenfassung Nach FÄllung auf geeigneten, mit Phosphonium- und Arsoniumsalzen getrÄnkten Reagenspapieren sind noch 0,5 g Osmium in 0,5–1 ml Lösung röntgenfluorimetrisch bestimmbar. Die Arbeitsbedingungen und Genauigkeit des Verfahrens werden angegeben. Auf die Möglichkeit der Bestimmung von Pt, Pd und Ir nach dem gleichen Verfahren wird hingewiesen.IX. Mitteilung: diese Z. 177, 420 (1960). 相似文献
995.
Athanassios Tavlaridis und Rolf Neeb 《Fresenius' Journal of Analytical Chemistry》1978,292(2):135-140
Zusammenfassung Darstellung, Extinktionskoeffizienten, thermogravimetrisches Verhalten und Dampfdrukke von 11 Di(trifluoräthyl)dithiocarbamatochelaten von analytischem Interesse werden angegeben.
Gas-chromatographic elemental analysis via Di(trifluoroethyl) dithiocarhamatochelatesI. Thermogravimetric behaviour and vapour pressure of some Di(trifluoroethyl) dithiocarbamatochelates
Summary Preparation, absorptivities, thermogravimetric behaviour and vapour pressure of 11 di(trifluoroethyl)dithiocarbamatochelates of analytical interest are reported.
Die Untersuchungen wurden in dankenswerter Weise durch Mittel der Deutschen Forschungsgemeinschaft und des Verbandes der chemischen Industrie unterstützt. Für die Gewährung eines Promotionsstipendiums sei der Friedrich-Ebert-Stiftung ebenfalls gedankt. Herrn Prof. Dr. G. Gattow danken wir für anregende Diskussionen, Herrn Prof. Dr. M. Dräger für die Hilfe bei der Durchführung der Rechnungen und für die Erstellung des Rechenprogramms. 相似文献
996.
997.
The synthesis of the 2,4,6-tri-tert-butylphenyl(halogenmethylene)phosphanes 4a—d from the tri-tert-butylphenylphosphane 1 and trihalogenomethanes 2a—d is described. Tri-tert-butylphenyl(difluoromethylene)phosphane 8a and the analogous (diiodomethylene)-phosphane 8d are obtained by dehalogenation of the chloro(trifluoromethyl)phosphane 7 and dehydrohalogenation of the triiodomethylphosphane 10 . The first different halogeno-substituted (bromochloromethylene)phosphane 8e leads after metallation with lithiumbis (trimethylsilyl)phosphide 13 and elimination of lithiumchloride to the phosphaalkyne 16 . Direct addition of chlorotrimethylsilane to the metallated 8e yields the 2,4,6-tri-tert-butylphenyl(chloro(trimethylsilyl)-methylene)phosphane 17 . 相似文献
998.
Gion Calzaferri Rolf Gleiter Karl-Heinz Knauer Erika Rommel Erika Schmidt Hans Behringer 《Helvetica chimica acta》1973,56(2):597-609
Irradiation of O-analogs of thiathiophthenes yield a photoproduct which reverts thermally to the starting material. Kinetic measurements for this thermal reaction yield Ea values in the range of 10–15 kcal/mol and Δ S* values between ?16 and ?41 eu. Based on NMR. and IR. results the structure of the photoproduct is established. The electronic spectra of the starting material and of the photoproduct are discussed. The experimental results are compared with MO-calculations. 相似文献
999.
The photoelectron spectra of 1,3-diazaadamantane (1) and 1,3-diaza-6-methyleneadamantane (2) have been measured. An analysis of the spectra based on a ZDO model indicates that the ordering of the n-orbitals in 1 is b2(n?λσ) above a1(n+?λσ). The splitting of b2 and a1 in 1 is dominated by the through space interaction. These results are confirmed by semiempirical calculations of the Extended Hückel and MINDO/3 type. An analysis of the PE spectrum of 1,3-diazaadamantanone(6) (5) indicates that in 5 the inductive effect of the CO group is dominant. 相似文献
1000.
Rolf Brönnimann Fritz K. Kneubühl 《International Journal of Infrared and Millimeter Waves》1984,5(4):531-536
The thermal spectral emission from ferromagnetic iron observed at normal incidence and with the magnetization parallel to its surface is partially linearly polarized. Measurements of the new even magneto-optic effect have been performed in the spectral range from 1.8 m to 5 m wave-length. 相似文献