European Journal of Mass Spectrometry最新文献

Liquid injection field desorption ionization (LIFDI) proves the extraordinary softness of the ionization process combined with a convenient sample supply under the exclusion of moisture and air. LIFDI-mass spectrometry (MS) is used for organometallic and other seriously air-sensitive compounds forming intact ions without substantial fragmentation. Unprecedented molecular radical anions M^-• are presented along with well-known intact M^+• radical cations. Furthermore closed shell cations [C]⁺ and adduct ions like [M + H]⁺ or [M + Alkali]⁺ are gently transferred from the solid emitter surface into the gas phase. Anions [A]^- or [M - H]^- are accessible by LIFDI-MS at medium field strengths. Ion pairs [C]⁺[A]^- are separately detected by positive and negative mode LIFDI-MS, respectively. Here we give an overview of the different ion types accessible by LIFDI-MS. For the first time the field ionization/desorption of solar cell electron acceptor compounds is shown to deliver M^-• and M^2-• radical ions.

Silyl anions are crucial building blocks in silicon chemistry and are frequently used in organosilicon chemistry. These so-called silanides are negatively charged three-coordinate species, isoelectronic to carbanions. In this contribution, we synthesized already literature known and unknown anionic silicon species. Here we focused on silyl substituted silyl anions with different substituted silicon atoms like hydrogen, methyl, and methoxy groups. Furthermore, we investigated these species with liquid injection field desorption ionization mass spectrometry.

In this study the use of negative electrospray ionisation mode as a confirmation tool for identifying derivatized amino acids using LC-ESI-MS, was evaluated. The derivatization reagent was based on azobenzene N-hydroxysuccinimide carbamate. The results indicate that even though negative ionisation mode produced less intense peaks, the ratio of peak area of quantifier ion (obtained in positive mode) to the qualifier (or identifier) ion measured in negative mode meets the requirements established by two prominent validation guidelines: SANTE/11312/2021 and 2002/657/EC. Therefore, the use of product ions obtained via negative transitions as qualifier ions, while using product ions from positive transitions as quantifier ions is a fruitful approach that widens the choice of transitions to choose from for obtaining suitable qualifier ions. This methodology was applied to the LC-ESI-MS/MS determination of amino acids in different beverages (tomato juice, watermelon juice, kvass).

Society's concerns about the citizens' exposure to possibly dangerous environments have recently risen; nevertheless, the assessment of indoor air quality still represents a major contemporary challenge. The volatile organic compounds (VOCs) are among the main factors responsible for deteriorating air quality conditions. These analytes are very common in daily-use environments and they can be extremely hazardous to human health, even at trace concentrations levels. For these reasons, their quick detection, identification, and quantification are crucial tasks, especially for indoor and heavily-populated scenarios, where the exposure time is usually quite long. In this work, a Gas Chromatography - Ion Mobility Spectrometry (GC-IMS) device was used for continuous monitoring indoor and ambient air environments at a large-scale, due to its outstanding levels of sensibility, selectivity, analytical flexibility, and almost real-time monitoring capability. A total of 496 spectra were collected from 15 locations of a university campus and posteriorly analysed. Overall, 23 compounds were identified among the 31 detected. Some of them, like Ethanol and 2-Propanol, were reported as being very hazardous to the human organism, especially in indoor environments. The achieved results confirmed the suitability of GC-IMS technology for air quality assessment and monitoring of VOCs and, more importantly, proved how dangerous indoor environments can be in scenarios of continuous exposure.

Zanubrutinib (BGB-3111) belongs to the class of irreversible inhibitors of Bruton's tyrosine kinase (BTK) for treating B-cell malignancies. A validated assay with excellent sensitivity, selectivity, and simplicity is required to measure plasma concentration and investigate its pharmacokinetics. The plasma of mice containing zanubrutinib and roxithromycin (internal standard) was processed with acetonitrile for protein precipitation. Then the supernatant was analyzed by high-performance liquid chromatography coupled with a triple quadrupole mass spectrometer using electrospray ionization in the positive mode. Zanubrutinib was given to mice intragastrically at 30 mg/kg to determine its pharmacokinetic parameters. The method was verified and showed good linearity in the range of 0.1-100 ng/mL. The method's sensitivity, accuracy, and precision were all within acceptable bounds. By this method, the pharmacokinetic profile of zanubrutinib in mouse plasma was measured.