Dehydration reactions are typically favored in microdroplets due to the relatively dry environment at the air–water interface. However, we demonstrate that cyclodesulfurization may outcompete dehydrat...

This study evaluated the micro-homogeneity of seven different commercially available nanoparticulate pressed pellets based on a CaCO3 matrix and their utility for quantitative elemental mapping of bio...

The long-term fate of tire and road wear particles (TRWP) significantly governs the distribution of tire-related chemicals. In addition to previous lab experiments a field study is performed, exposing...

Samples from eight regions of Hainan Island and seven passion fruit orchard types were collected and tested for 12 pesticides. Bee health and honey dietary risks were assessed for sensitive groups. A...

Indole-3-acetic acid (IAA) is a natural hormone found in all plants and can also be used as a plant growth regulator, which is banned in the EU. To differentiate between its natural presence and pesticide usage, the origin and fate of IAA during coffee roasting were studied. Green beans from the Coffea arabica and Coffea canephora varieties were spiked with a stable isotope precursor, 13C11-tryptophan, and roasted to different degrees. Liquid and gas chromatography coupled with mass spectrometry were used to analyze the degradation products. Alkaline hydrolysis determined free and bound IAA proportion in the coffee samples. The study found that IAA levels increased during roasting, forming indole-3-acetaldehyde and further degrading into 3-methylindole. Hydrolysis experiments showed that IAA was released from the coffee matrix, with higher amounts released during longer roasting times. These results indicate that IAA naturally occurs in green coffee and is not likely due to pesticide use.

ConspectusMass spectrometry imaging (MSI) has transformed our ability to explore molecular distributions in biological tissues with high chemical specificity and sensitivity. Despite significant advances in this field, the absence of separation prior to analysis leads to isomeric and isobaric overlaps, posing a major analytical challenge. To enhance chemical specificity and enable isomer differentiation, tandem mass spectrometry, ion mobility spectrometry, chemical complexation, and derivatization strategies are increasingly integrated into MSI workflows.Ambient ionization MSI techniques provide both chemical and spatial information under native or near-native conditions, enabling rapid, label-free molecular imaging of complex biological samples with minimal sample pretreatment. Among the most promising ambient MSI techniques is nanospray desorption electrospray ionization (nano-DESI), a method that relies on localized liquid extraction directly from biological tissue sections. We have successfully implemented custom-designed nano-DESI platforms on multiple commercial mass spectrometers to enable molecular identification at each pixel of the image and facilitate isomer-selective mass spectrometry imaging (iMSI).This Account highlights recent advances in iMSI using nano-DESI. Key developments include the integration of nano-DESI with multiple reaction monitoring on a triple quadrupole mass spectrometer to differentiate isomeric lipids in biological tissues. We also describe the integration of photoinitiated derivatization and metal ion complexation strategies to enable isomer-selective imaging using structure-specific fragments generated by collision induced dissociation. Furthermore, high-resolution separation of lipid isomers was achieved by coupling nano-DESI with trapped ion mobility spectrometry, demonstrating the value of gas-phase separation for iMSI. These innovations have significantly expanded the analytical capabilities of MSI critical to probing the spatial organization of isomeric lipids and metabolites in biological systems. We also discuss future directions, including new complexation strategies and the integration of nano-DESI with data-independent acquisition and parallel accumulation serial fragmentation technologies. Collectively, these advances establish nano-DESI iMSI as a powerful and versatile tool in the evolving field of spatial metabolomics and lipidomics.

Models to predict the environmental fate of micropollutants are needed for alternatives assessment and safe-by-design efforts. Wastewater treatment plants (WWTPs) are the main barrier to prevent micro...

Vacuum ultraviolet photoionization (VUV-PI) mass spectrometry offers an isomer-selective and universal ionization with minimal fragmentation detection of organics in complex chemical systems such as pyrolysis and combustion. Here, we report a state-of-the-art experimental setup of a universal catalytic microreactor combined with a molecular beam to investigate the thermocatalytic oxidation of a heterogeneous system relevant for probing reactions at gas–solid interfaces. In strong contrast to traditional off-line analytical methods, this technique is capable of identifying and quantifying short-lived species (radicals) as well as stable products to decipher initial reaction steps via the detection of nascent products. The thermocatalytic oxidative degradation of exo-tetrahydrodicyclopentadiene (JP-10), a high energy-density hydrocarbon fuel, over solid titanium–aluminum–boron reactive mixed metal nanopowder (Ti-Al-B RMNP) is exploited to showcase potential applications. Overall, some 59 nascent gas-phase products are identified via photoionization efficiency (PIE) curves, including oxygenated species and hydrocarbons comprising closed-shell molecules and radicals. The critical temperature for complete oxidative decomposition of JP-10 was lowered by 450 K from 1400 K to 950 K, indicating an efficient thermocatalytic action of Ti-Al-B nanoparticles on JP-10. The enabling of a universal chemical microreactor along with VUV-PI mass spectrometry broadens the applicability of this technique to hydrocarbon fuel oxidation and pyrolysis characterization. This isomer-selective sensitive probing along with the detection of radical transients makes the aforementioned technique superior to other conventional analytical techniques such as microflow tube and pyrolysis-gas chromatography coupled with mass spectrometry for investigating similar pyrolysis reactions and comprehensive quantification.

HFPO-DA ammonium salt (GenX) is used to replace the environmentally persistent perfluorooctanoic acid (PFOA), but its effects on fish lipid metabolism…

Liquid crystal monomers (LCMs), increasingly recognized as emerging environmental pollutants, pose potential risks to human health. However, their tra…

Aspartame (APM) is demonstrated to facilitate the dissemination of antibiotic resistance genes and react with residual chlorine in tap water to form c…

Scientific Reports - Postpartum metabolomics profile predicts 8-years postdelivery women’s subclinical atherosclerosis measures

Whey protein hydrolysates, the industrial byproducts from the dairy industry, contains various bioactive peptides. When added to infant formula, it ma…

Background: Diabetic kidney disease (DKD) is a critical microvascular complication of diabetes mellitus. As a clinical therapeutic drug for DKD, the t…

There is a great controversy about the definition of fresh nut of Areca catechu L. around the world. The study created a database-affinity ultra-high-performance liquid chromatography-quadrupole-or...

Abstract. An Ultra Performance Liquid Chromatography - Mass Spectrometry/Mass Spectrometry (UPL­MS/MS) method for simultaneous determination of 8, 11, 12,

Fluoxetine, a widely prescribed antidepressant, is frequently detected in marine environments, exposing marine invertebrates to this emerging contamin…

The Orm family proteins inhibits serine palmitoyltransferase —the enzyme that catalyzes the first step in sphingolipid synthesis. In S. cerevisiae, the two Orm proteins are thought to function redunda...

Aim: This study aimed to establish a method for the simultaneous quantification of 7 bile acid components in mouse feces and to apply this method to investigate the variations in bile acid profiles...

A longstanding limitation of Hydrogen-Deuterium Exchange Mass Spectrometry (HDX-MS) has been the difficulty to accurately measure amide exchange with single amide resolution. Excitation of peptides or...

Nucleotidases are enzymes that play vital roles in nucleotide pool balance and purine and pyrimidine metabolism across various tissues. Two major forms of nucleotidases, 5’-nucleotidases (5’-NTs) and ...

Gemcitabine (Gem) is a Food and Drug Administration-approved chemotherapeutic agent used for the treatment of a wide variety of cancers. Yet, its clinical application is constrained by poor pharmacok...

Rationale This paper evaluates the use of a plasma source coupled to an LTQ mass spectrometer for the analysis of explosive residues from soil samples, and in the process examines the advantages and.....

Chemical industrial parks are regions of high-intensity volatile organic compound (VOC) emissions, yet studies of their emission characteristics have been constrained by limited real-time data. Here, ...