Concentrating on Chromatography

Liquid chromatography–mass spectrometry (LC-MS) has been the backbone of modern analytical workflows for decades — but what if one of its most trusted components is also its biggest bottleneck?In Episode 50 of Concentrating on Chromatography, host Dave Oliva sits down with Daniel DeBord, Chief Technology Officer at MOBILion Systems, to explore how high-resolution ion mobility may be changing the way scientists think about precursor isolation in tandem MS.Traditional MS/MS workflows rely on quadrupole filtering to isolate precursor ions prior to fragmentation. But because quadrupoles operate as mass filters, they routinely discard the vast majority of incoming ions — often more than 99% — contributing to signal loss, slower acquisition speeds, and chimeric spectra in complex mixtures.Daniel explains how Structures for Lossless Ion Manipulations (SLIM) technology introduces an additional gas-phase separation step between LC and MS — enabling:* Near-lossless ion transmission through the instrument* Separation based on size-to-charge rather than mass-to-charge* Cleaner MS/MS spectra with reduced spectral chimerism* LC gradient compression without sacrificing analytical resolution* Peak capacities comparable to 20–30 minute LC separations — achieved in milliseconds For chromatographers, this raises an important question:If critical separations can occur in the mobility domain, how much chromatography do we actually need?Daniel also discusses:* Whether HRIM could supplement or replace quadrupoles in future instruments* Applications in proteomics, metabolomics, and environmental analysis* Integrating ion mobility into triple quadrupole workflows* Challenges around method development and data processing* What the next generation of LC-ion mobility-MS platforms may look likeThank you  @SeparationScience  for collaborating with me on this episode!---🎧 Guest: Daniel DeBord, CTO, MOBILion Systems🎙 Podcast: Concentrating on Chromatography📌 Episode 50

Light can heal. Light can power devices. But light can also destroy molecules.In this episode of Concentrating on Chromatography, we sit down with Kshmeya Chopra to explore how phthalocyanines — highly conjugated macrocycles used in photodynamic therapy, sensing, and organic electronics — respond to prolonged light exposure.Using UV–Vis spectroscopy, Kshmeya and her research team systematically investigated how:• The central metal (Zn²⁺ vs In³⁺)• Degree of fluorination• Axial ligands• Solvent environment (EtOAc vs DMSO)influence photostability under two-sun irradiation conditions.By monitoring changes in the Q-band absorbance over time and calculating extinction coefficients using Beer–Lambert law, the team uncovered clear structure–property relationships governing light-induced degradation.We discuss:🔬 How UV–Vis spectroscopy tracks molecular breakdown🧪 Aggregation vs true chemical degradation☀️ Why fluorination improves photostability⚖️ Zinc vs indium coordination effects📊 Extinction coefficients and what they reveal about macrocycle behavior🧬 How LC–MS and HRMS could identify degradation products🎓 Advice for undergraduate students entering photochemistry and analytical researchThis conversation bridges spectroscopy, materials chemistry, and analytical science — showing how subtle molecular design choices dramatically impact stability and real-world application potential.If you’re interested in photochemistry, UV–Vis analysis, chromatography, or rational molecular design, this episode is for you.🎙️  @ChromatographyTalk  explores the intersection of analytical chemistry, instrumentation, and applied molecular science.Subscribe for more conversations on LC-MS, GC-MS, spectroscopy, and chemical problem-solving.#spectroscopy
#Photodegradation
#Photostability
#Phthalocyanines
#Fluorination
#Highresolutionmassspectrometry
#Analyticalchemistrypodcast

In this episode of Concentrating on Chromatography, we sit down with Lindsay Repka to discuss how LC-MS and GC-MS transformed her lab’s approach to photoredox chemistry.What began as a project to develop a visible-light photocrosslinking handle unexpectedly led to a major discovery: the solvent (DMF) was reacting with the photocatalyst itself. Using high-resolution LC-MS, Lindsay’s team observed multiple solvent adducts forming — sometimes with complete catalyst consumption. That discovery reshaped their research direction.Drawing from her ACS Northeast presentation and this in-depth conversation, Lindsay explains:🔬 How photoredox catalysts become activated under visible light📊 Why LC-MS was essential when NMR couldn’t resolve complex mixtures📈 How to design reproducible calibration curves for percent catalyst remaining📉 Why extracted ion chromatograms (EIC) outperform total ion chromatograms (TIC) at low concentrations⚗️ How solvent activation chemistry led to selective N-demethylation🧪 Why GC-MS with an internal standard streamlined reaction screening📐 What relative response factors mean — and why they can’t always be assumed constant🧑‍🔬 Practical tips for improving reproducibility (microbalances, deoxygenated solvents, temperature control)This episode is a rare deep dive into both LC-MS and GC-MS within the same research project, showing how chromatography-driven insight can turn unexpected degradation into productive new reactivity.If you work in:* Photoredox chemistry* Reaction optimization* Mass spectrometry method development* Catalyst screening* Academic synthetic chemistry…this conversation will resonate.🧪 Key Topics Covered* Photocatalyst stability in DMF, DCE, and MeCN* Demethylation under mild visible-light conditions* High-resolution Q-TOF LC-MS quantitation* Internal standard methodology in GC-MS* Signal-to-noise improvement using extracted ion chromatograms* Reaction reproducibility and quality control strategy🎙 About the GuestLindsay Repka is a chemistry professor at Middlebury College whose research explores photoredox chemistry, catalyst stability, and visible-light-driven transformations. Her lab emphasizes both mechanistic insight and hands-on student training in advanced analytical instrumentation.If you enjoy conversations at the intersection of chromatography and real-world chemistry research:👍 Like💬 Comment with your LC-MS / GC-MS questions🔔 Subscribe for more episodes of

In this episode of Concentrating on Chromatography, David speaks with Francis Femi Oloy about using chromatography to uncover hidden pollutants in real-world water systems.Femi’s team analyzed polychlorinated biphenyls (PCBs) in six major rivers in southwestern Nigeria — compounds that were banned decades ago but still persist in the environment. Using a workflow that many analytical labs will recognize — liquid–liquid extraction, cleanup, rotary evaporation, nitrogen blowdown, and GC-ECD detection — they quantified 25 PCB congeners at trace levels and linked the results to ecological and human health risk.📌 In this conversation, we cover:• Why legacy pollutants like PCBs still show up today• Choosing GC-ECD vs LC-MS for halogenated compounds• Liquid–liquid extraction and matrix cleanup strategies• Why sample concentration is critical for dilute environmental samples• How rotovap + nitrogen blowdown work together without losing volatile analytes• Seasonal trends (why wet season levels were higher)• Translating concentration data into meaningful risk assessmentsThis episode is perfect for anyone working in:Chromatography • Environmental analysis • Sample prep • Trace analysis • GC methods • Analytical chemistryIf you enjoy practical discussions about real laboratory workflows and how chromatography solves real problems, subscribe to Concentrating on Chromatography. 🔬 Paper discussed: Polychlorinated biphenyls (PCBs) in rivers of Southwestern Nigeria: sources, seasonal distribution, and assessment of human health risks# 🔔 More episodesSubscribe for more interviews with scientists using chromatography and mass spectrometry to solve real-world challenges.

How do you see proteins, metals, and disease processes inside real tissue — and still trust the numbers?In this episode of Concentrating on Chromatography, David sits down with Monique Mello, analytical chemist, educator, and LA-ICP-MS imaging specialist, to explore how laser ablation ICP-MS (LA-ICP-MS) and immuno-mass spectrometry imaging (iMSI) are transforming pathology, environmental science, and translational research.Monique shares her journey from public-health and pathology labs in Brazil to environmental and biomedical research in Australia — and explains why metrology, traceability, and defensible measurements are the foundation of meaningful science.We dive into her work developing multiplexed elemental imaging methods that allow researchers to quantify multiple proteins at once in tissue — revealing interactions that traditional single-marker methods miss. Her studies show how LA-ICP-MS can map dystrophin-glycoprotein complex proteins in muscular dystrophy and track elemental distributions like zinc in Alzheimer’s disease tissue.We also discuss something many labs overlook: sample preparation and immunolabelling can change the chemistry you’re trying to measure. Monique’s research demonstrates how staining steps can redistribute endogenous metals and why rigorous validation is critical for trustworthy data.If you care about chromatography, mass spectrometry, or analytical chemistry that genuinely impacts patients and communities, this episode is for you.In this conversation, we cover:• What LA-ICP-MS imaging is and how it works• Multiplexed antibody tagging with lanthanides for quantitative tissue imaging• Why metrology and uncertainty matter more than “pretty data”• Common analytical failures (and why sample prep causes most of them)• Elemental mapping in muscular dystrophy and Alzheimer’s research• How immunolabelling and coverslipping can perturb endogenous metals• Teaching analytical chemistry for real-world problem solvingWho this is for: Analytical chemists • Mass spectrometrists • Chromatographers • Pathology researchers • Environmental scientists • Students entering the field