Concentrating on Chromatography

An unfamiliar peak. An inconclusive library search. A molecule that’s visible with one detector but missing from another. How do you figure out what’s actually in your sample?

James Little joins David Oliva and Candi Gokey on Concentrating on Chromatography to explore the detective work behind identifying unknown compounds. Drawing on nearly five decades of mass spectrometry experience, including his career at Eastman Chemical and current work supporting NIST and Wiley’s spectral libraries and software, James explains how he combines chemical reasoning with GC-MS, LC-MS, and NMR.

He shares the story of a mystery molecule whose electrospray signal disappeared in the presence of acetonitrile, recalls receiving a 55-gallon sample when he needed only a microliter, and explains why a top library match is a clue—not proof.

In this episode:

• Why identifying one unknown peak starts with understanding the whole sample.
• When GC-MS and LC-MS provide complementary information.
• How accurate mass, isotope patterns, and hybrid library searches help narrow down possible structures.
• What NMR can resolve when mass spectrometry leaves multiple possibilities.
• How sample preparation and solvent choices influence what you detect.
• Why curiosity, persistence, and skepticism matter as much as the instruments.

For chemistry students and laboratory scientists alike, this conversation offers an inside look at how an experienced analytical chemist turns unfamiliar data into defensible answers.

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Undergraduate researcher Kody Coyne is building a safer, hydrazine-free way to make nitrogen–nitrogen, nitrogen–oxygen, and nitrogen–sulfur bonds. Because every product is a brand-new compound, he has to invent the chromatography method to purify it.

Kody is a biochemistry major and varsity swimmer at Monmouth College. In this episode he explains how he uses a custom C18 reversed-phase HPLC method to identify his product peak. He then uses that same information to decide between reversed-phase and normal-phase flash chromatography. He also explains how he double-checks every result with HPLC, FTIR, and NMR, and what he learned when his older flash system reported a negative absorbance.

In this episode

• How Kody learned Schlenk lines, flash chromatography, and HPLC by doing the work himself
• How he landed his research project through Monmouth's summer research program
• Why the hydrazine-free bond chemistry could make drug synthesis cheaper and safer
• Why novel compounds get flash chromatography first, with recrystallization tested later
• How a custom C18 HPLC method helps him pick the right flash stationary phase and gradient
• How he uses HPLC to confirm which flash fractions contain product
• What a clean trace looks like, and why he doesn't trust any single instrument
• Why chromatography slows work on new molecules but not on well-documented ones
• Why working under nitrogen keeps unwanted peaks out of the chromatogram
• The hot dog cooked in a benchtop microwave synthesizer
• His advice to undergraduates: don't wait until you're an expert

If you're an undergraduate about to run your first flash column or HPLC sample, his advice is simple: don't wait until you're an expert to start.

Concentrating on Chromatography is hosted by David Oliva of Organomation.

Chris Freye, Ph.D., is a staff scientist in the High Explosives Science and Technology group at Los Alamos National Laboratory, where he uses GC×GC, UHPLC, UHPLC-IMS, and high-resolution mass spectrometry to study how high explosives and plastic-bonded explosives (PBXs) change over time.

In this episode, Chris discusses his path from rock climbing in the Pacific Northwest to a PhD under GC×GC pioneer Robert Synovec at the University of Washington, and how that training shaped his current work at Los Alamos. He walks through the unique safety and security realities of national lab chemistry, from handling gram-scale samples to retrieving material from magazines holding thousands of pounds of explosives, and explains why sample prep always starts with the scientific question rather than the instrument.

The conversation covers why LC has long been the gold standard for explosives analysis and why it only tells half the story, how his team developed vacuum GC×GC to elute volatile explosives before they decompose, and the accidental discovery that a GC inlet can double as an aging oven — compressing three-year explosive aging studies into two hours. Chris also explains why his team started finding PFAS in high explosives materials through fluoropolymer binders, the extraction method they had to invent after standard EPA protocols failed, and how chemometric tools like Alteration Analysis and Fisher ratio analysis let them distill billions of data points into a simple yes-or-no answer about chemical change.

Whether you work in chromatography, mass spectrometry, materials science, or just want a rare look inside high-explosives research, this episode covers the instrumentation, the chemistry, and the day-to-day reality of the work.

When DNA is absent, incomplete, or difficult to interpret, what other evidence can help forensic investigators make meaningful connections?

In this episode of Concentrating on Chromatography, David Oliva speaks with Dr. Candice Bridge of the University of Central Florida and the National Center for Forensic Science about the emerging field of forensic lubricant analysis.

Dr. Bridge explains how chemical residues from sexual lubricants can support sexual-assault investigations by helping connect a victim, suspect, condom wrapper, or crime scene—especially when a usable DNA profile is unavailable. She discusses why DNA is not always the “silver bullet” people expect, why preserving limited evidence is essential, and how forensic laboratories prioritize the least destructive analysis first.

The conversation also explores the analytical chemistry behind lubricant evidence:

• The chemical differences among water-, silicone-, oil-, and natural/edible-based lubricants
• Why personal-care products such as lotions and oils can complicate forensic interpretation
• The limitations of conventional GC-MS for high-mass polymers such as PDMS and PEG
• How DART-TOF mass spectrometry enables rapid screening of complex forensic samples
• Why extraction from cotton swabs and other evidence substrates remains a critical challenge
• How solvent polarity affects recovery of lubricant components
• How likelihood ratios, population studies, and retail-market data could help assess the rarity and evidentiary value of a recovered lubricant residue
• Practical advice for undergraduate students considering careers in forensic science and analytical chemistry

Dr. Bridge also shares why she chose an underdeveloped research area, what it takes to build a new forensic discipline, and why students should pursue socially important scientific questions—even when funding and established protocols have not yet caught up.

Guest: Dr. Candice Bridge
Host: David Oliva
Podcast: Concentrating on Chromatography

Follow the podcast for conversations on chromatography, mass spectrometry, forensic science, sample preparation, laboratory technology, and careers in analytical chemistry.

He built a gas chromatograph and mass spectrometer small enough to fit in a carry-on suitcase, then hauled it up a 43-meter tower in 100-degree Alabama heat to catch invisible forest chemicals in real time.

Austin "Augie" Dobrecevich, a PhD researcher at the University of Washington, joins Candi and David to break down how his ultra-fast GC captures a full chromatogram every single second, isomer-speciating the biogenic VOCs (like alpha-pinene, beta-pinene, and limonene) that trees release into the atmosphere. Those compounds don't just disappear; they react with ozone and each other, eventually seeding the massive summer thunderstorms that roll over the southeast.

Augie walks through why traditional chemical ionization mass spec struggles to tell chemical isomers apart, how his fast GC front end solves that blind spot, and the engineering trade-offs required to make the whole system run on less power than a vacuum cleaner. The conversation also opens up into where this technology could go next, from oceanographic research to coral reef VOC sampling, and closes with a candid look at the patent process: provisional patents, university tech transfer offices, IP strategy, and the leap from writing research papers to pitching a business case.

Whether you're deep into analytical chemistry or just curious how scientists are learning to read the invisible chemistry of a forest, this episode covers both the technical detail and the real story of turning a lab prototype into something the world might actually use.

Guest: Austin Dobrecevich

Hosts: Candi Gokey and David Oliva

Arielle Cocozza, National Technical PFAS Lead at ALS USA Environmental, joins David Oliva and Candi Gokey to break down the current state of PFAS analysis — from her unconventional path out of a physics degree into environmental chemistry, to standardizing PFAS methods across a national lab network.In this episode, Arielle explains what PFAS actually are and why their fluorine-carbon bonds make them so persistent, walks through LC-MS/MS vs. GC-MS/MS selection for different PFAS classes (including fluorotelomer alcohols and volatile fluorocarbons), and discusses column chemistry choices like C18 and pentafluorophenyl phases. The conversation dives deep into 6PPD-quinone — the tire-wear-particle degradation product linked to coho salmon die-offs — and how EPA fast-tracked Draft Method 1634 in response. Arielle also covers the Total Oxidizable Precursor (TOP) assay, EPA's new ultra-short direct-injection Method 1633/563 workflows, sample volume miniaturization, automation trends in extraction, and the patchwork of state-by-state PFAS regulations on food packaging and biosolids ahead of federal rulemaking.

Mauricio Caraballo, PhD, director of the MSCollaboratory at UC San Diego, joins Candi Gokey and host David Oliva to unpack how untargeted LC-MS/MS metabolomics reveals hidden chemistry in coral reefs, fish, and ocean water. They dig into molecular networking, GNPS, and how free mass spec training is helping marine scientists worldwide analyze samples they couldn't otherwise decode.

Links: mscollaboratory.ucsd.edu | Mauricio Caraballo: linkedin.com/in/mauricio-caraballo-4b5577176

Mechanical engineer Mason Chilmonczyk, PhD (Andson Biotech) joins host David Oliva to explain why sample prep — not the mass spec itself — is the biggest bottleneck in LC-MS and native MS workflows. Mason breaks down the DynaChip, a microfluidic device that shrinks hours of buffer exchange into seconds, and shares how "democratizing" mass spec is opening the door for cell therapy manufacturers to catch analytical blind spots that traditional workflows miss. A must-listen for anyone working in native mass spec, biopharma analytics, or cell therapy development.

Dr. Emanuela Gionfriddo, Associate Professor of Chemistry at the University at Buffalo, joins host David Oliva to explore solid phase microextraction (SPME), green analytical chemistry, and PFAS analysis. Trained in Professor Janusz Pawliszyn's lab at the University of Waterloo — where SPME was invented — she shares how deep SPME theory reshaped her research and now drives her lab's work on environmental and biological chemistry.In this episode, Emanuela discusses how SPME complies with the 12 principles of green analytical chemistry, why her lab consistently produces the least waste in her department, and how biomimetic SPME devices using natural biopolymers like alginic acid and chitin reveal how pollutants bioaccumulate in the environment. She also covers her lab's PFAS research, including a surprising study testing mascara for PFAS contamination, the analytical challenges of volatile PFAS detection, and why field-deployable PFAS quantification isn't quite ready yet.Topics covered: SPME fundamentals, green analytical chemistry, PFAS detection, biomimetic extraction, mixed-mode sorbents, GC×GC for volatile PFAS, and emerging microplastics research.Connect with Dr. Emanuela Gionfriddo: https://www.linkedin.com/in/emanuela-gionfriddo-60492659/Subscribe to Concentrating on Chromatography for more conversations with leading separation science researchers.

On this episode of Concentrating on Chromatography, hosts David Oliva  @Organomation  and Candice Gokey are joined by Matthew Lewis  @Bruker  to unpack the new hybrid metabolomics workflow born from Bruker's acquisition of  @biocrates  .For 20 years, mass spectrometrists have had to choose between targeted quantitation and untargeted discovery. Matthew explains how chemical derivatization, high-resolution mass spec, and Biocrates' 1,000+ metabolite kits now let researchers get both — without running samples twice.Topics covered: - Why "there's no such thing as an untargeted platform, just an uninformed one" - How the Biocrates MX Quant Kits standardize sample prep and derivatization - NMR vs. mass spectrometry for metabolomics — and why electrospray ionization is metabolomics' "biggest Achilles heel" - Data-dependent (DDA) vs. data-independent (DIA) acquisition, explained simply - Trapped Ion Mobility Spectrometry (TIMS) and collisional cross-section (CCS) as a "gas-phase chromatography" tool for resolving isomers and interferences - In silico derivatization software for annotating derivatized metabolites - The "digital metabolome archive": building future-proof, reanalysis-ready 4D data (MS1 + retention time + CCS + MS/MS) for AI-ready datasets - Why standardization — not just new features — is what will move the metabolomics field forwardMatthew also shares insights from Bruker's collaboration with Dr. Michael Witting at the Helmholtz Institute, and discusses the real-world sample constraints (biobanks, field research, precious cohorts) driving demand for do-more-with-less workflows.Guest: Matthew Lewis, Bruker — https://www.linkedin.com/in/matthew-reese-lewis/Co-host: Candice Gokey — https://www.linkedin.com/in/cmgokey15/Host: David Oliva, Organomation#Metabolomics #MassSpectrometry #Chromatography #Bruker #Biocrates #Lipidomics #SystemsBiology #TIMS #IonMobility