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991.
992.
In this study, application of a fused silica capillary column for analysis of major mutagenic heterocyclic compounds found in cooked foods was investigated. 相似文献
993.
O. Bobleter 《Chromatographia》1996,43(7-8):444-446
Summary In November 1995, theDeutsches Museum, the world's largest technical museum, opened a new branch in Bonn, devoted to achievements after 1945. There, the first gas chromatographic system used by Erika Cremer and Fritz Prior, in 1945–47, in Innsbruck, is exhibited. The new display is described and the early activities of Erika Cremer and her students are summarized. 相似文献
994.
995.
Summary Arsenic in marine samples was determined by gas chromatography with electron capture detection after derivatization with 2,3-dimercaptopropanol.
Biological tissues and sediments were analyzed after acid decomposition. For sea water, arsenic was preconcentrated by coprecipitation
with hydrous iron (III) oxide. The results obtained by this approach compare favourably with the certified values of the reference
materials analyzed.
Presented at the 15th International Symposium on Chromatography, Nürnberg, October 1984 相似文献
996.
Sven Jacobsson 《Journal of separation science》1984,7(4):185-190
An experimental method for the analysis of volatile organic compounds in polymers is described. The technique involves dynamic headspace sampling, collection, and concentration of the volatiles in a cold trap, followed by capillary column gas chromatography/mass spectometry. Flow switching is carried out by the Deans switching technique. Four technical polymers used as pharmaceutical packaging materials have been analyzed in order to demonstrate the method. 相似文献
997.
From measurements of the solubility of argon in aqueous solutions of the complexion electrolyte t-[Co(en)2NCSCl]Br at 25°C, the Setschenow parameter for this system is found to be +0.336. Using the scaled-particle theory of the salt effect with this value ofk
5 and the Waddington crystal radius of the Br– ion, 1.98 Å, the radius of the complex cation is calculated to be 3.71 Å. This value is in reasonably good agreement with that estimated from scale models of the t-[Co(en)2-NCSCl]+ cation, about 3.9 Å. It is somewhat larger than the radius calculated from various semiempirical equations relating the molal volume of an ion at infinite dilution to its radius; values of r obtained in this manner range from 3.32 to 3.66 Å.Abstracted, in part, from D.P.'s M.S. thesis, June 1971. 相似文献
998.
Using methods of potentiostatic coulometry, the solubility of thallium(I) iodate in 0.1m sodium perchlorate and in 0.1m perchloric acid was determined over the temperature range 2–75°C. Thermodynamic functions were calculated for the dissociation of thallium(I) iodate into its aqueous ions. From the solubilities in the acid solutions the dissociation constant of iodic acid was calculated over the temperature range, along with the value of –1.83±0.07 kcal-mol–1 for the standard enthalpy change for the dissociation. 相似文献
999.
1000.
J. Curvers F. Maris C. Cramers C. Schutjes J. Rijks 《Journal of separation science》1984,7(7):414-422
Quantitative analysis of steroids and their metabolites in urine samples calls for increased speed of sample clean-up, of the derivatization procedure, and of separation. A fast procedure for sample pretreatment, which can be performed within 8 hours, is introduced and evaluated. It is shown that use of fast pretreatment in combination with narrow bore columns, which are compatible with existing instrumentation, can considerably increase, laboratory throughput. The effect of different sample introduction techniques (e.g. splitless, on-column, and moving needle) on column efficiency and resolution is demonstrated and discussed. 相似文献