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...

Online monitoring of the appearance of the intermediates and products during chemical reactions is helpful to understand reaction mechanisms. Various analytical tools including nuclear magnetic resonance spectroscopy, Raman spectroscopy and mass spectrometry (MS) have been employed for the study. MS is one of the most promising means among analytical tools that can provide information of mass-t...

mass spectrometry method is developed and validated for the simultaneous quantitation of three major phenolic acids including 1,5-dicaffeoylquinic acid (1,5-DCQA), 3,4-dicaffeoylquinic acid (3,4DCQA), and 3,5-dicaffeoylquinic acid (3,5-DCQA) in rat plasma. All analytes and internal standard (bergeninum) are extracted from plasma samples by liquid–liquid extraction with isopropanol. The chromato...

Relative biological effectiveness (RBE) is an important quantity in planning particle beam cancer therapy. In general, the RBE describes the biological effectiveness of a given primary beam with respect to a reference photon irradiation. RBE varies not only for different primary beams but also with depth in the target for a given beam modality. It is not a quantity that easily lends itself to m...

A novel technique has been developed to build vessels for liquid xenon ionization detectors entirely out of ultra-clean fluoropolymer. We describe the advantages in terms of low radioactivity contamination, provide some details of the construction techniques, and show the energy resolution achieved with a prototype all-fluoropolymer ionization detector.

The high performance liquid chromatography-electrospray ionization-mass spectrometry method has been applied to the measurement of bile acid transport activities in membrane vesicles obtained from a human bile salt export pump expressing Sf9 cells. The amounts of bile acids transported using the human bile salt export pump expressing Sf9 cells were determined using liquid chromatography-electro...

Cauxin is a carboxylesterase-like glycoprotein excreted as a major component of cat urine. Cauxin contains four putative N-glycosylation sites. We characterized the structure of an N-linked oligosaccharide of cauxin using nano liquid chromatography (LC)-electrospray ionization (ESI) and matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight mass spectrometry (MALDI-QIT-T...

Abbreviations: PTMs=post-translational modifi cations; PPIs=protein-protein interactions; SDS-PAGE= sodium dodecyl sulfate-polyacrylamide gel electrophoresis; 2D-PAGE=two-dimensional polyacrylamide gel electrophoresis; MS=mass spectrometry; ESI=electrospray ionization; MALDI=Matrix Assisted Laser Desorption Ionization; ESI-MS=electrospray ionization mass spectrometry; MALDI-MS=MALDI mass spectr...

background & aim: identification, characterization and detection of medicinal plants chemical composition are very important for phytochemical scientific source. sumac is one of the medicinal plants in the world that uses for industrial and pharmacological application. in this study, chemical composition of rhus coriaria has been investigated. experimental: chemical composition of the matu...

The technique of gas-liquid chromatography-chemical ionization mass spectrometry can easily identify trace peaks and unresolved peaks on gas-liquid chromatography, utilizing MH(+) ions of chemical ionization mass spectra. In polyunsaturated fatty acid methyl esters such as C22:5 and C22:6, the determination of molecular weights that are difficult to determine by electron impact mass spectrometr...