Liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESIMS/MS) is one of the most prominent analytical techniques owing to its inherent selectivity and sensitivity. In LC/ESI-MS/MS, chemical derivatization is frequently used to enhance the MS/MS detectability. The derivatization improves the separation and ionization efficiency. Moreover, the generated derivatives give par...

Modern determination techniques for pesticides must yield identification quickly with high confidence for timely enforcement of tolerances. A protocol for the collection of liquid chromatography (LC) electrospray ionization (ESI)-quadruple linear ion trap (Q-LIT) mass spectrometry (MS) library spectra was developed. Following the protocol, an enhanced product ion (EPI) library of 240 pesticides...

BACKGROUND The Bio-Rad QuantaPhase II radioassay (BR), used for 25 years to measure total folate (TFOL) concentrations for the National Health and Nutrition Examination Survey (NHANES), will be discontinued in 2007. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) or a microbiologic assay (MA) will be used in the future. METHODS We measured folate species by LC-MS/MS and TFOL by MA a...

Cortisol is an important diagnostic marker for the production of steroid hormones, and accurate measurements of serum cortisol are necessary for proper diagnosis of adrenal function. A candidate reference method involving isotope dilution coupled with liquid chromatography/mass spectrometry (LC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS) has been developed and critically e...