Most hyphenated analytical approaches that rely on liquid chromatography-MS require relatively long separation times, produce incomplete resolution of oligosaccharide mixtures, use eluents that are incompatible with electrospray ionization, or require oligosaccharide derivatization. Here we demonstrate the analysis of heparin oligosaccharides, including disaccharides, ultralow molecular weight ...

the occurrence of emerging fusarium mycotoxins beauvericin (bea), enniatins (enns) (a, a1, b, b1), fusaproliferin and moniliformin was evaluated by a liquid chromatography/electrospray ionization-tandem mass spectrometric (lc/esi-ms/ms) technique in 65 domestic rice samples produced in gilan and mazandaran provinces in ir iran. the results showed that 46% of the samples were contaminated with a...

Combined data of photoelectron spectra and photoionization efficiency curves in the near threshold ionization region of isolated ion pairs from [emim][Tf(2)N], [emim][Pf(2)N], and [dmpim][Tf(2)N] ionic liquid vapors reveal small shifts in the ionization energies of ion-pair systems due to cation and anion substitutions. Shifts toward higher binding energy following anion substitution are attrib...

Ion-mobility spectrometry (IMS) in conjunction with radioactive ionization sources has been employed for field-portable applications for the past two decades. Recently, electrospray ionization (ESI) sources have been shown as a viable ionization source with IMS instruments, enabling the analysis of many nonvolatile compounds. Introduction of a liquid-sheath-flow ESI source enabled the direct an...

A method is described for the direct quantitation of phosphatidylcholine molecular species by reverse phase high-performance liquid chromatography employing flame ionization detection. The method is shown to be applicable to plan phosphatidylcholine. The molecular species are separated with a C18 column eluted in an isocratic mode. Detection by a commercially available flame ionization detector...

Herbicides are chemical substances that are applied to agricultural soils, gardens, lawns, or plants to destroy or to prevent the growth of undesirable vegetation. The herbicides included in this review are generally synthetic organic compounds that are ingredients in commercial herbicide products that were designated active during late 2002 in the U.S. Environmental Protection Agency's databas...

A major limitation in quantitative analysis with electrospray ionization mass spectrometry (ESI-MS) is represented by the so-called matrix effects in which the matrix coextracted with the analytes can alter the signal response, causing either suppression or enhancement, resulting in poor analytical accuracy, linearity, and reproducibility. In the direct electron ionization liquid chromatography...

Sensitive chromatographic methods were developed for the quantitative analysis of secondary metabolites in Hypericum perforatum (St. John's wort) and Rhodiola rosea (Golden root, rose root) extracts. Sample preparation methods were developed for plant, cell culture and biotransformation suspension matrixes. High performance liquid chromatography (HPLC) was used for the separation of analytes, a...

A novel means of combining thin-layer chromatography (TLC) with laser desorption/ionization mass spectrometry using a liquid matrix is proposed. Surface-assisted laser desorption/ionization (SALDI) mass spectrometry, which uses a mixture of a micrometer-sized carbon powder (graphite or activated carbon, the SALDI solid) and 15% sucrose/glycerol, dissolved in an equal volume of methanol (SALDI l...