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A method is described for the determination of the novel hydroxymethyl glutaryl coenzyme A reductase inhibitor RP 61969 (I) and its hydrolysis product, the dihydroxy acid RP 62420 (II), in human plasma. A structural isomer of I is used as internal standard. Both I and II were extracted from acidified plasma with diethyl ether. The dried residues were reconstituted in the high-performance liquid chromatography mobile phase and chromatographed on a 5 microns ODS2 column. The mobile phase used was aqueous dipotassium phosphate +tetra-n-butyl ammonium bromide (both 10 mM)-acetonitrile-methanol (60:40:5, v/v). At a flow-rate of 1.5 ml min-1 and ambient temperature, the retention time of II is 3.5 min, that of the internal standard is 5 min, and that of I is 8 min. The method has been validated and applied to the assay of plasma samples resulting from a cell-plasma distribution experiment in human whole blood. 相似文献
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R. Veeraraghavan N. S. Hon A. G. Page 《Journal of Radioanalytical and Nuclear Chemistry》2004,261(1):69-72
A method based on synergic extraction has been evolved for the recovery of tens of milligrams of americium from analytical
wastes in 7-8M HNO3 medium containing excess uranium as a two step procedure viz., (1) separation of uranium by contacting with TBP in dodecane
and (2) recovery of americium by an extraction-cum-strip cycle using a synergic mixture of PMBP-TBP in dodecane after decreasing
the acidity of the solution. Other transition metals such as iron found in significant proportion were separated from Am by
using the difference in the kinetics of extraction of iron and americium into HPMBP-TBP-dodecane mixture by short duration
contacts. About 99% of Am could be recovered into about 20% of its initial volume.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Comprehensive studies have been carried out on the extraction behaviour of thorium matrix vis-a-vis 17 trace metallic elements using a novel extractant viz. Cyanex-923. The near total extraction of thorium and quantitative separation of these metals has been established using inductively coupled argon plasma–atomic emission spectrometry (ICP–AES). The recovery of few representative elements has been confirmed by radio-active tracer studies. The studies carried out here have enabled determination of μg/l amounts of all analyte elements with a precision of better than 1% RSD with prior chemical separation from as low as 1 g thorium sample in just five chemical extractions. 相似文献
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Roger J. Greathead Rod S. Mason Keith R. Jennings Janet A. Page Robert J. Pryce 《Journal of mass spectrometry : JMS》1985,20(2):110-114
The behaviour of gibberellic acid (GA3) under electron impact and chemical ionization conditions has been examined. The tendency of GA3 to undergo pyrolysis by the loss of the elements of water and carbon dioxide has been identified. Two methods of sample introduction can be used to minimize the occurrence of this pyrolysis. Accurate mass measurement allows the composition of the pyrolysis product to be determined and metastable techniques confirm the structure of this product to be epi-allogibberic acid rather than its isomer allogibberic acid. This result corrects a misconception in the literature and illustrates the advantage of metastable methods compared with accurate mass measurements, for the determination of small structural differences within a molecule. 相似文献