Journal of Chromatography B

A simple, highly sensitive ultra-performance liquid chromatography- electrospray ionization-mass spectrometry (LC-ESI-MS) method has been developed to quantify of withanolide B and obakunone (IS) in guinea pig plasma and tissues, and to compare the pharmacokinetics and tissue distribution of withanolide B in normal and psoriasis guinea pigs. After mixing with IS, plasma and tissues were pretreated by protein precipitation with methanol. Chromatographic separation was performed on a C18 column using aqueous (0.1% formic acid) and acetonitrile (0.1% formic acid) solutions at 0.4 mL/min as the mobile phase. The gradient program was selected. Detection was performed on a 4000 QTRAP UPLC–ESI-MS/MS system from AB Sciex in the multiple reaction monitoring (MRM) mode. Withanolide B and obakunone (IS) were monitored under positive ionization conditions. The optimized mass transition ion-pairs (m/z) for quantitation were 455.1/109.4 for withanolide B and 455.1/161.1 for obakunone.

Quantification of sofosbuvir and ledipasvir in human plasma. UPLC-MS/MS method for analysis in human plasma. Application to fasting and fed bioequivalence studies.

AF4-UV-MALS-ICP-MS intensities of iron oxide nanoparticles spiked into rat blood cells and plasma

These clinical data were obtained based on our established HPLC-fluorescence/ultraviolet detection of normetanephrine, metanephrine, 3-methoxytyramine and creatinine in spot urine samples. All statistical analysis and diagnostic methods for pheochromocytomas and paragangliomas were analyzed based on these data.

The research data uploaded include two tables. Table 1:the original data for precision and accuracy. Table 2: the plasma concentration of mPEG2000-PDLLA2500-COOH after a single caudal vein intravenous injection of 5 mg/kg mPEG2000-PDLLA2500-COOH to rats.

Compared to the ISCID approach, fragmentation efficiency of the in-quadrupole collision was much higher. Only a few low abundance DEX-specific fragments were found at the maximum in-source energy, and many DEX chains remained intact in ion source.

Untreated chromatograms, centrifugal partition chromatogram was copied from a SIC CPC 240 workstation, with the preparative liquid chromatogram was copied from a Waters 2545 workstation.

This is the original LC-MS experimental data, organized in multiple Excel worksheets, which the R script reads directly for various computation and visualization analysis.

The MS² library includes over 4,000 fragmentation spectra of 506 standard metabolites for 6 different normalized collision energies (NCEs). A list of compounds is provided in the related supplementary material. The data was generated with an Orbitrap mass spectrometer (QExactive, ThermoFisher Scientific, Bremen, Germany). The data format (.db) is compatible with Library Manager (ThermoFisher) or mzVault (ThermoFisher). The MS² library will be available in an open access format on the Website of our group (https://www.cbbm.uni-luebeck.de/forschungszentrum/core-facilities/bioanalytic-core-facility.html). The LC library includes information about the chromatographic behavior of 294 metabolites. A total score and scores for sensitivity, peak width, peak asymmetry and retention are listed. For the score system, please see the related manuscript/supplementary material. Retention factors (k values) and retention times are available as a resource for elution order. The LC library ID corresponds to Table S2 of the related manuscript/supplementary material. It is possible to filter for one or more metabolites of interest in order to find the most suitable method for analysis.

Sweat was collected from the forearms of male participants. Sweat was aliquoted and frozen after 0, 30, 60, and 90 minutes at either room temperature or body temperature. Samples were lyophilized to dryness, reconstituted, and run by HILIC-MS. Data was acquired on a Q Exactive HF using polarity switching at 15,000 resolution.