We discovered novel calibrants, several 2,2,6,6-tetraalkylpiperidinyl derivatives, for accurate mass measurements by electrospray ionization mass spectrometry (ESI). These compounds showed excellent performance as internal calibrants for the accurate mass measurement in ESI-MS, without problems arising from differences in the ionization efficiencies between the analytes and calibrants.

Mid-infrared laser ablation of water-rich targets at the maximum of the 2.94 μm absorption band is a two-step process initiated by phase explosion followed by recoil pressure induced material ejection. Particulates and/or droplets ejected by this high temperature high pressure process can be ionized for mass spectrometry by charged droplets from an electrospray. In order to gauge the internal e...

Mid-infrared laser ablation of water-rich targets at the maximum of the 2.94 mm absorption band is a two-step process initiated by phase explosion followed by recoil pressure induced material ejection. Particulates and/or droplets ejected by this high temperature high pressure process can be ionized for mass spectrometry by charged droplets from an electrospray. In order to gauge the internal e...

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...

Mass Spectrometry The ionization of N-protonated Verapamil by electrospray (ESI) is investigated in the Communication (e202116794) W. Scott Hopkins et al. using differential mobility spectrometry (DMS). spectral behaviour caused protonation-induced chirality.

Electrospray ionization mass spectrometry has been used to study protein interactions driven by noncovalent forces. The gentleness of the electrospray ionization process allows intact protein complexes to be directly detected by mass spectrometry. Evidence from the growing body of literature suggests that the ESI-MS observations for these weakly bound systems reflect, to some extent, the nature...

The methods of extraction, separation and analysis of alkaloids and indole glucosinolates (GLs) ofIsatis tinctoria were reviewed. Different analytical approaches such as High-pressure Liquid Chromatography (HPLC), Liquid Chromatography with Electrospray Ionization Mass Spectrometry (LC/ESI/MS), Electrospray Ionization Time-Of-Flight Mass Spectrometry (ESI-TOF-MS), and Nuclear Magnetic Resonance...

It has always been assumed that electrical contact at the capillary outlet is a necessary requirement when coupling capillary electrophoresis (CE) with electrospray ionization mass spectrometry (ESI-MS). In this study, we used a pulled bare-capillary tip as the ESI emitter, but neither was it coated with any electrically conductive materials nor was a high external voltage applied on its outlet...

A comparison of the mass spectral response for myoglobin, cytochrome c, and lysozyme is presented for laser electrospray mass spectrometry (LEMS) and electrospray ionization-mass spectrometry (ESI-MS). Analysis of multicomponent protein solutions using nonresonant femtosecond (fs) laser vaporization with electrospray postionization mass spectrometry exhibited significantly reduced ion suppressi...

Six synthesized 6-nitroquipazine derivatives were examined by electron ionization (EI) and electrospray ionization (ESI) mass spectrometry in positive and negative ion mode. The compounds exhibit high affinity for the serotonin transporter (SERT) and belong to a new class of SERT inhibitors. The EI mass spectra registered in negative ion mode showed prominent molecular ions for all the compound...