A combination of complementary analytical techniques has provided valuable information on the physicochemical properties of lipid-DNA complexes such as their size, shape, structure and surface charge. The experimental conditions for producing small and stable lipid-DNA complexes were determined. These complexes consist of spherical primary particles of approximately 60 nm in diameter connected to each other by DNA strands to form small clusters of approximately 70-200 nm in diameter.
View Article and Find Full Text PDFFlow injection electrospray ionization tandem mass spectrometric methods for succinylacetone (SA) in 250 microL urine, using d5-SA as internal standard, and in 3 mm dried bloodspots, using 13C4-SA as internal standard, are described. Selectivity and sensitivity of analysis is achieved by the use of a mono-Girard T derivative. Measured SA infant urine normal range (n=20) is 0.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
December 2003
High pressure liquid chromatography with a narrow bore C8 column has been used to separate pristanic, phytanic and very long chain fatty acids, important in the diagnosis of peroxisomal disorders, for their accurate isotope dilution quantification by tandem mass spectrometry. The fatty acids, isolated from plasma, were analysed as trimethylaminoethyl ester (quaternary ammonium) derivatives. Analysis time was 2.
View Article and Find Full Text PDFAcetyl trimethylaminoethyl ester iodide derivatives have been used to selectively analyze isomeric long-chain hydroxy fatty acids by electrospray ionization tandem mass spectrometry (ESI-MS/MS). The binary derivatives of 2-, 3-, 12- and 16-hydroxypalmitic acids afford remarkably different product ion spectra. Further discrimination between isomers is possible by acylating with pivaloyl chloride.
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