high performance liquid chromatography (hplc) with diode array detection (dad) and electrospray ionization tandem mass spectrometry (esi/ms/ms) was used to analyze the main components in the methanol extract of fructus aurantii (fa) and the metabolites in rat biological samples after oral administration of the methanol extract of fa. there were 31 constituents identified in the extract of fa in...

Studying protein O-glycosylation remains an analytical challenge. Different from N-linked glycans, the O-glycosylation site is not within a known consensus sequence. Additionally, O-glycans are heterogeneous with numerous potential modification sites. Electron transfer dissociation (ETD) is the method of choice in analyzing these glycopeptides since the glycan side chain remains intact in ETD, ...

What is the lineage relation among the cells of an organism? The answer is sought by developmental biology, immunology, stem cell research, brain research, and cancer research, yet complete cell lineage trees have been reconstructed only for simple organisms such as Caenorhabditis elegans. We discovered that somatic mutations accumulated during normal development of a higher organism implicitly...

A new method for the quantification of benzoxazinone derivatives in extracts of wheat foliage and root samples using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS-MS) is described. Using this method, the characterization, separation, and quantitative detection of a mixture of six naturally occurring 1,4-benzoxazin-3(4H)-one derivatives, including the hydroxam...

IN T RO DU C T IO N LC-ESI-MS is currently the most prevalent separation technique employed in neonatal screening, used to diagnose over 30 inborn errors of amino acid, organic acid, and fatty acid metabolism. Recent analytical improvements in this approach have reduced the false-positive result rate, as compared to other conventional techniques. 2 However, UPLC/MS has not yet been used for ana...

Due to the lack of a gold standard method in canine lipoprotein analysis, it is unclear whether canine high-density lipoprotein (HDL) and low-density lipoprotein (LDL) can be accurately evaluated by the lipoprotein analysis methods used for dogs. This study investigated whether the ultracentrifugation-precipitation (U-P) method was suitable as a gold standard method for analyzing canine lipopro...

A method has been developed for the sensitive and rapid analysis of polycyclic aromatic hydrocarbons (PAHs) in environmental samples using liquid chromatography time-of-flight mass spectrometry as well as the selective atmospheric pressure laser ionization (APLI) process (LC-APLI-MS). Upon analyzing 34 PAHs, the limits of detection of this method were found to range from 0.008 to 1.824 pg (0.02...

Approximately 25% of psoriasis patients have an inflammatory arthritis termed psoriatic (PsA). There is strong interest in identifying and validating biomarkers that can accurately reliably predict conversion from to PsA using novel technologies such as metabolomics. Lipids, particular, are key disease. We sought develop a liquid chromatography-mass spectrometry (LC-MS) method be used conjuncti...

To evaluate bile acid (BA) metabolism in detail, we established a method for analyzing BA composition in various tissues and intestinal contents using ultra performance liquid chromatography/electrospray ionization mass spectrometry (UPLC/ESI-MS). Twenty-two individual BAs were determined simultaneously from extracts. We applied this method to define the differences in BA metabolism between two...