A rapid and sensitive liquid chromatography–tandem mass spectrometry (LC-MS) method was developed for the determination of enalapril and enalaprilat in human plasma. Detection of analytes was achieved by tandem mass spectrometry with electrospray ionization (ESI) interface in positive ion mode which was operated under the multiple-reaction monitoring mode. Sample pretreatment was involved...

An isotope dilution liquid chromatography/tandem mass spectrometry is proposed as a reference method to determine the level of tyrosine in human serum. The advantages of this method include simple sample preparation without derivatization, the selective detection of compounds of interest in complex matrices, and the use of an isotopically labeled analogue as an internal standard. Tyrosine and i...

Protein identification from tandem mass spectra is one of the most versatile and widely used proteomics workflows, able to identify proteins, characterize post-translational modifications, and provide semiquantitative measurements of relative protein abundance. This manuscript describes the concepts, prerequisites, and methods required to analyze a tandem mass spectrometry dataset in order to i...

In order to assist with the development of more selective and sensitive methods for thyroid hormone analysis the [M-H]- anions of the iodothyronines T4, T3, rT3, (3,5)-T2 and the non-iodinated thyronine (T0) have been generated by negative ion electrospray mass spectrometry. Tandem mass spectra of these ions were recorded on a triple-quadrupole mass spectrometer and show a strong analogy with t...

conclusions cd5l might be a useful biomarker for early diagnosis of hcc in hcv cirrhotic patients. lrg and hp α2 isoforms could be potential markers for distinguishing viral hcc. our results also further support the presence of varying molecules involved in hepatocarcinogenesis in hbv when compared with hcv infection. patients and methods two-dimensional polyacrylamide gel electrophoresis combi...

Several approaches to ion activation in tandem mass spectrometry have been developed in recent years for use in ion trapping instruments that allow for conditions to be reached wherein rates of ion activation and deactivation are comparable. These approaches are deÐned as slow heating methods and include continuous-wave laser infrared multiphoton dissociation, dissociation driven by blackbody r...