John Chasse

Articles by John Chasse

On the suggestion that per- and polyfluoroalkyl substances (PFAS) affect both lactation and the human metabolome, perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) were measured in the milk of 425 participants from the New Hampshire Birth Cohort Study using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

A recent study compared different workflows for extracting, purifying, and analyzing bone proteins using liquid chromatography with tandem mass spectrometry (LC–MS/MS), including an in-StageTip protocol previously optimized for forensic applications, and two protocols using novel suspension-trap technology (S-Trap) and different lysis solutions. LCGC International discussed this work with Noemi Procopio of the School of Law and Policing and the Research Centre for Field Archaeology and Forensic Taphonomy at the University of Central Lancashire (UK), corresponding author of the paper that resulted from this study.

Ultra-high performance liquid chromatography, coupled with a fluorescence detector, was used in a recent study to profile 23 amino acids and glutathione in juices of four internationally relevant grape varieties grown under different soil and climatic conditions.

A recent study analyzed the variability in plasma quinidine (QND) concentrations using population pharmacokinetics to determine an effective and safe dosage regimen for Thoroughbred horses suffering from atrial fibrillation (AF).

An investigation of the accumulation of primary and secondary metabolites, including bioactive compounds, to characterize the qualitative traits of blood oranges at the time of harvest was conducted, with liquid chromatography identifying and quantifying simple sugars, and spectrophotometric analysis identifying and quantifying organic acids, polyphenols, and flavonoids.

LCGC International recently spoke to Tomáš Rozsypal of the Nuclear, Biological and Chemical Defence Institute of the University of Defence (Vyskov, Czech Republic) about his work utilizing gas chromatography in researching the persistence of A-234 nerve agent on indoor surfaces, and the paper that resulted from it.

In a recently published study, liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was used to analyze 100 Turkish apple samples for the presence of 225 different pesticide residues during the 2022-2023 harvest season.

A recent joint study between the Department of Forensic Science of the College of Criminal Justice at Sam Houston State University (Huntsville, Texas) and the Department of Criminal Justice of the School of Social Sciences at Ming Chuan University, (Taipei, Taiwan) developed artificial intelligence (AI) by transfer learning in a convolutional neural network (CNN), GoogLeNet, with the image classification AI fine-tuned to create intelligent classification systems to discriminate samples containing gasoline residues from burned substrates.

Although automated peak detection functionalities are available in commercially accessible software, utilizing visual inspection and manual adjustments to achieve optimal true positive rates is often necessary. A recent study conducted by the Department of Chemical Engineering at the Indian Institute of Technology (Delhi, India) used liquid chromatography-mass spectrometry (LC–MS) to distinguish hetero-variants (glycoforms) resulting in a monoclonal antibody (mAb) able to be characterized, revealing discernible peaks at the intact level. LCGC International spoke to Anurag Rathore, corresponding author for the article, about his department’s findings.

Researchers from the Department of Bioscience and Technology for Food, Agriculture and Environment at the University of Teramo (Italy) used gas chromatography-mass spectrometry (GC-MS) investigated the contribution of Kluyveromyces marxianus to the gross composition and aroma profile of cow cheeses.

A recent study examined three drug overdose deaths resulting from an Italian prison riot during the initial wave of the SARS-CoV-2 pandemic. To ascertain the nature of these deaths, a comprehensive toxicological analysis was conducted, employing gas chromatography-mass spectrometry to reveal high concentrations of various substances in the biological fluids of the deceased inmates.

A recent study focused on identifying molecular markers capable of discriminating between different origins and, at the same time, predicting their sensory attributes adopting a sensomics approach. An untargeted method was adopted, based on the coupling of ultra-high performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS), followed by the application of chemometric tools for the selection of 71 discriminating molecular markers for six origins.

A recent study determined the insecticidal activity of essential oils (EOs) from leaves of P. aduncum cultivated in southeastern Brazil, collected during the dry and rainy seasons, against fleas. Through this research, researchers hope to promote the utilization of these natural resources, particularly those now in cultivation and available for industry, in ways that align with traditional practices.

A recent study investigated the significance of quantifying amino acids in minute sweat volumes using high performance liquid chromatography (HPLC) with fluorescence (FL) detection, offering a non-invasive and efficient way to screen for diseases by detecting amino acids in sweat, even with minimal sweat volumes.