Determination of tributyltin and 4-hydroxybutyldibutyltin chlorides in seawater by liquid chromatography with atmospheric pressure chemical ionization-mass spectrometry.

Determination of valproic acid in serum by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry.

ON-LINE SOLID-PHASE EXTRACTION AND LIQUID CHROMATOGRAPHY/PARTICLE BEAM-MASS SPECTROMETRY FOR DEGRADATION STUDIES OF SOME POLAR PESTICIDES IN WATER

An on-line automated method for photodegradation studies of isoproturon, diuron, atrazine, fenitrothion, and metoxuron by means of liquid chromatography/mass spectrometry (LC/MS) with particle beam (PB) interface is described. Surface water samples were first spiked with 50 µg/l of each pesticide and then exposed to the radiation of the medium-pressure mercury lamp. Next, in regular intervals o...

Relative Determination Approach to the Metabolites of Protoberberine Alkaloids in Rat Urine by Liquid Chromatography Tandem Mass Spectrometry for the Comparative Studies on Rhizome coptidis and Zuojinwan Preparation

The lack of authentic standards has limited the quantitative analysis of herbal drugs in biological samples. The present work demonstrated a practicable strategy for the assay of herbs and their metabolites independent of authentic standards. A liquid chromatography–electrospray ionization–mass spectrometry (LC–ESI–MS) method for the qualitative and quantitative determination of the metabolites...

ID/NI - 06 Dielectric Barrier Discharge Microplasma-Ionization for Liquid Chromatography / Mass Spectrometry

The coupling of liquid chromatography and mass spectrometry (LC/MS) has been established as one of the most powerful tools in analytical chemistry and has resulted in important advances especially in biomedical and biochemical research. The predominantly used interfaces are electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI). Non-polar compounds, however, are diffi...

Derivatization in liquid chromatography/mass spectrometric analysis of neurosteroids.

Liquid chromatography/mass spectrometry (LC/MS) is now considered to be the most promising analytical method for the determination of biological substances, especially nonvolatile or highly polar substances. However, some compounds do not show enough sensitivity in LC/MS and soft-ionization methods commonly used in LC/MS, such as electrospray ionization (ESI) and atmospheric pressure chemical i...