A simple, sensitive, and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determining urinary creatinine was developed and used to evaluate 24 h urine samples collected during an exposure study. Urine (1 microL) was diluted with methanol and then directly applied to LC-MS/MS. Under electrospray ionization (ESI) conditions, the transition molecules of creatinine and ...

A robust and complete workflow for metabolic profiling and data mining was described in detail. Three independent and complementary analytical techniques for metabolic profiling were applied: hydrophilic interaction chromatography (HILIC–LC– ESI–MS), reversed-phase liquid chromatography (RP–LC–ESI–MS), and gas chromatography (GC–TOF–MS) all coupled to mass spectrometry (MS). Unsupervised method...

Nanoscale reversed-phase liquid chromatography (LC) combined with electrospray ionization-tandem mass spectrometry (ESI-MS/MS) has been used as a method for the direct identification of multiple cytochrome P450 (P450) isoforms found in male and female rat liver. In this targeted proteomic approach, rat liver microsomes were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis ...

This paper describes the analysis procedure and results for environmental herbicide samples by a negative ESI LC-MS/MS method. After the preparation of aqueous and soil samples, the extracts are directly injected into a high performance liquid chromatography system coupled to negative eletrospray ionization (ESI-) tandem mass spectrometry. The sample preparation incorporates modified hydrolysis...

The application of continuous flow-extractive desorption electrospray ionization (CF-EDESI), an ambient ionization source demonstrated previously for use with intact protein analysis, is expanded here for the coupling of reversed phase protein separations to mass spectrometry. This configuration allows the introduction of charging additives to enhance detection without affecting the chromatogra...

The optimal conditions for the separation and detection of a mixture of 18 phenethylamine/tryptamine derivatives were determined, using liquid chromatography/UV-absorption (LC/UV) and liquid chromatography/electrospray ionization mass spectrometry (LC/ESI MS) methods, respectively. Complete separation could be achieved within approximately 25 min using gradient elution (A, 0.1% formic acid aque...

The methods of extraction, separation and analysis of alkaloids and indole glucosinolates (GLs) ofIsatis tinctoria were reviewed. Different analytical approaches such as High-pressure Liquid Chromatography (HPLC), Liquid Chromatography with Electrospray Ionization Mass Spectrometry (LC/ESI/MS), Electrospray Ionization Time-Of-Flight Mass Spectrometry (ESI-TOF-MS), and Nuclear Magnetic Resonance...

BACKGROUND Jujube extract is commonly used as a food additive and flavoring. The sensory properties of the extract, especially sweetness, are a critical factor determining the product quality and therefore affecting consumer acceptability. Small molecular carbohydrates make major contribution to the sweetness of the jujube extract, and their types and contents in the extract have direct influen...

A Dielectric Barrier Discharge Ionization (DBDI) LC/MS interface is based on the use of a low-temperature helium plasma, which features the possibility of simultaneous ionization of species with a wide variety of physicochemical properties. In this work, the performance of LC/DBDI-MS for trace analysis of highly relevant species in food and environment has been examined. Over 75 relevant specie...

γ-Aminobutyric acid (GABA) is an inhibitory neurotransmitter having anti-anxiety, stress-reducing and sleep-enhancing effects. The blood GABA concentration has the potential to become a diagnostic index for depression schizophrenia. In this study, we developed method quantification of in human serum by liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) combine...