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ABSTRACT: This chapter describes two different methods using reversed-phase HPLC with electrochemical detection on a boron-doped diamond (BDD) working electrode for the direct, routine, sensitive and simultaneous measurement of a number of aminothiols, disulfides, and thioethers, in either plasma or tissue homogenates.
Methods in molecular biology (Clifton, N.J.) 01/2010; 594:327-39.
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ABSTRACT: This paper describes the development and qualification of a method capable of analyzing inorganic ions as salts and counter-ions of both active pharmaceutical ingredients and other compounds such as lysine. The use of a polymeric zwitterionic column with a binary high-performance liquid chromatography gradient enables the separation of several anions and cations in a single run. A generic gradient (method #1) was developed and validated with respect to specificity, correlation, intermediate precision, accuracy, and sensitivity (limits of quantitation and detection) for four anions and two cations. Furthermore, the ability to alter chromatographic selectivity by simple gradient manipulation (without altering the mobile phase composition or column type) is demonstrated for nine anions and three cations (method #2). The simultaneous measurement of cations and anions at the parts per billion level using the Corona charged aerosol detector with zwitterionic chromatography-polymeric hydrophilic interaction chromatography is a viable alternative to traditional techniques used for ion analysis.
Journal of chromatographic science 08/2009; 47(7):534-9. · 0.88 Impact Factor
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ABSTRACT: A gradient HPLC-charged aerosol detection method was applied to the measurement of different lipids including: free fatty acids, fatty alcohols, glycerides, steroids, phospholipids, and fat-soluble vitamins. An algal oil sample is used as an example. Charged aerosol detection offers a new approach to the routine analysis of any nonvolatile lipid. It shows low ng (on column) sensitivity, a dynamic range of over four orders of magnitude, good reproducibility, gradient compatibility, and similar analyte response for nonvolatile species, independent of chemical structure. Furthermore, charged aerosol detection uses mobile phases that are fully compatible with LC-MS--enabling both detectors to be used in a "lipidomics platform."
Methods in molecular biology (Clifton, N.J.) 01/2009; 579:469-82.
