HPLC/ESI-MS analyses of alcohol solutions of ampicillin and amoxicillin have shown that the two drugs react very readily with alcohols (methanol and ethanol) at room temperatures, without the presence of any catalyst. Products of methanolysis were detected even when methanol was used as a mobile phase, in HPLC/ESI-MS analysis of a water solution of ampicillin and amoxicillin. Therefore, neither...

Two mass spectrometry methods, high-performance liquid chromatography combined on-line with electrospray ionization mass spectrometry (HPLC-ESI-MS) and electron-capture (EC) dissociation tandem mass spectrometry (MS-MS), were applied for structural analysis of bovine and human osteocalcins. Osteocalcin contains gamma-carboxyglutamic acid (Gla) residues, which bind metal ions, among its amino ac...

Researchers are increasingly turning to label-free MS1 intensity-based quantification strategies within HPLC-ESI-MS/MS workflows to reveal biological variation at the molecule level. Unfortunately, HPLC-ESI-MS/MS workflows using these strategies produce results with poor repeatability and reproducibility, primarily due to systematic bias and complex variability. While current global normalizati...

Harvested longan (Dimocarpus longan Lour.) fruit are susceptible to decay caused by both bacterial and fungal infections. Ochratoxin A (OTA) is a kind of mycotoxin produced by a number of fungi. In this study, OTA was extracted from longan fruit pulp by 80% methanol and then loaded on C-18 solid-phase extraction columns. The extract solution was then analyzed by high-performance liquid chromato...

Different separation (HPAEC, RP-HPLC, CE) and identification (MALDI-TOF-MS, ESI-MS(n)) techniques were compared to analyse oligosaccharides obtained after incubation of xyloglucan with endo-glucanase. It was possible to analyse xyloglucan oligosaccharides with each technique. Several techniques, including off line (HPAEC-MALDI-TOF-MS) or online (CE-ESI-MS(n), RP-HPLC-ESI-MS(n)) connection provi...

Antidesma bunius is an edible berry fruit with many benefits, such as natural antimicrobials, anticancer, dyes, etc. However, data on chemical content in the still limited. The purpose of this research to identify volatile compounds fruit. We extracted and analyzed A. fruit’s using GC-MS HPLC–DAD-ESI-MS methods. Forty-nine representing 99.91% total chromatogram’s relative peak area were detecte...

ingly undesirable, especially when alternative techniques based upon physicochemical substance properties are available. Toxins generally are analyzed using high performance liquid chromatography (HPLC) techniques with various unspecific detectors. Therefore, subsequent confirmation is needed to ensure that these methods do not yield any false responses. While enzyme immunoassay screens are ava...

Flavonoid fraction composition of Larix dahurica Turcz. knotwood was studied with HPLC-DAD/ESI-MS/MS. Dihydroquercetin, aromadendrin, dihydroisorhamnetin, eriodictyol and quercetin were revealed as its components.