Verdel's Q-2DMS aims to bring 2D mass spectrometry to more common hardware

Researchers at the University of Warwick and its spin-out Verdel Instruments have run two-dimensional mass spectrometry (2DMS) on a commercially available benchtop quadrupole time-of-flight (Q-TOF) instrument. They did it with an upgrade kit, not a dedicated machine. Their paper in Analytical Chemistry, by Wright, Cassidy, Colburn and O'Connor, describes what the team reports as the first such demonstration, and they call the implementation Q-2DMS.

That matters because of where 2DMS has lived until now. As Technology Networks' Alexander Beadle explains, the technique has only been achievable on Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometers, high-performance instruments found at specialized facilities. Verdel CEO Tim Wilson, an analytical chemist with more than 30 years in commercialization, says researchers have understood for years how powerful 2DMS is, but access has been the problem, because only the best-funded centers could afford the specialist hardware. In the launch announcement, he said Verdel's technology lets 2DMS run on benchtop instruments, a class of hardware that is widely available. "Any lab can now access this powerful technique."

If 2DMS moves onto more common hardware, that could change who gets to evaluate it. A lab director who never had a reason to price an FT-ICR could ask a smaller question: which of the lab's hardest samples lose information in its current workflow?

Wilson's framing is as much a commercial argument as a scientific one. If the method's value is already accepted, the remaining barrier is the instrument itself, and Chromatography Online states the appeal plainly: a method that once needed dedicated infrastructure can now be added as an upgrade to hardware already sitting on many groups' benches.

Frequency tags instead of a column

Start with the baseline. In a typical tandem mass spectrometry (MS/MS) workflow, chromatography isolates the analytes of interest, which are then fragmented one after another, and a spectrum is recorded for the fragments of each precursor. Selection happens in sequence, one ion at a time.

In 2DMS, ions sit in an ion trap and go through a sequence of radio-frequency excitation steps. That frequency encoding links each precursor to its fragments, so every fragment from every precursor can be measured at once.

Q-2DMS applies that idea on the Q-TOF by assigning every analyte its own frequency signature, linked to its mass-to-charge (m/z) ratio. When the analytes fragment, the product ions keep their parent's signature. A mathematical decoding step then works out which fragment came from which precursor, all from a single acquisition that has been neither separated nor filtered. The published study reports high-resolution MS/MS data obtained directly from complex mixtures without chromatographic separation or mass filtering.

The detail most likely to matter to the analyst at the bench comes from John Chasse's write-up in Chromatography Online: on first inspection, the output resembles an ordinary set of tandem mass spectra, the type an MS/MS user already knows how to read. A familiar readout suggests the retraining burden could fall mostly on method development, and much less on interpretation.

The decoding is what makes that possible. Without it, the signals would be an overlapping set too congested to interpret. With it, they become an ordered series of mass spectra comparable to what separation and filtering produce. In effect, the sorting a conventional workflow does with a column and a quadrupole over time, Q-2DMS does with mathematics after the fact.

Where the tenfold number applies

The headline result is that Q-2DMS kept up to tenfold more usable spectral information when analyzing closely related or near-isobaric compounds. SelectScience and Chromatography Online both report the figure, and both frame it the same way. Chromatography, precursor filtering and simplified data processing each make a spectrum easier to read, and each throws away signal the analyst never sees. Labmate Online's Alan Booth makes the same point: the loss happens without the analyst knowing what has been excluded.

The qualifier matters as much as the number. "Up to" and "near-isobaric" put the gain in a specific place: molecules so similar in mass and structure that separation and filtering are most likely to blur them together or drop them. For a lab whose difficult samples already resolve cleanly on liquid chromatography, the reported gain says less. For a lab whose inconclusive calls cluster around look-alike compounds, it points straight at the samples to use in a trial. The developers name four areas:

• Healthcare: faster identification of unexpected drug metabolites, which the developers tie to more personalized treatment
• Environmental monitoring: direct detection of PFAS and other emerging contaminants without pre-separation, aimed at speeding up water quality monitoring
• Drug control: rapid characterization of novel synthetic and designer drugs for forensic labs and regulators
• Drug development: finding unanticipated reaction products and impurities during medicinal chemistry and process work, to better understand reaction pathways and product purity

Read the list for its adjectives: unexpected, emerging, novel, unanticipated. Each use case involves a compound the analyst may not know to look for. A targeted method can only isolate a precursor someone chose in advance, so these are the cases where acquiring everything and sorting it out later would matter most.

There is a fair objection to all of this. The published coverage gives no figures for how the tenfold gain changes routine outcomes such as rerun rates, identification confidence or impurity calls, and those are the measures a quality manager actually reports. Until labs generate that data on their own samples, the tenfold figure describes what the instrument records. Whether it changes what a lab decides is still an open question.

A record that outlives the sample

The second selling point is quieter, and it may matter more to labs that handle irreplaceable material. Dr Shum Prakash, business development manager at Warwick Innovations, told SelectScience that Q-2DMS pairs its readouts with a complete time-stamped record of each sample. Researchers can go back to that record later without the original sample, which may have degraded by then. Chromatography Online singles out clinical, environmental and forensic samples, where material often runs out or degrades before every question has been asked.

Prakash credits "years of world-leading research" at Warwick for the result. The practical payoff, as SelectScience describes it, is that scientists can re-examine data as new questions arise without re-running precious or unstable samples.

Practically, this changes what an archived run is worth. A filtered acquisition can only answer the question that was set when the sample went in. A full acquisition could, in principle, answer a later one: a compound added to a screening list after the fact, say, or a confirmation requested once the sample itself is gone. That shifts some of the value of a test from the bench to the data archive. It also puts storage, file management and reprocessing software on the list of things a lab has to plan for.

Capturing everything puts the work on decoding

Verdel isn't alone in trying to measure more at once. In March, Carolyn Wilke reported in Chemical & Engineering News on MultiQ-IT, a prototype ion trap from Rockefeller University's Brian Chait and Andrew Krutchinsky. One version has 486 openings, and the team reports it trapped about 1,000 times more ions than the most advanced commercial instruments. Chait described it as a proof of concept and said the next job is working out how to handle and analyze everything it produces.

The problem Chait describes is the same one Q-2DMS targets. Today's instruments are "stunningly good," he said, "but we do everything rather serially." Most ion traps have one inlet and one outlet, which forces researchers to choose which ions to analyze; he compared it to catching a fish from Niagara Falls with a single bucket. Low-abundance molecules that might be important get missed, and Chait points out that "there is no correlation between the amount of a protein and its importance."

The Rockefeller fix is architectural. Over some 10 years the pair built and tested versions with anywhere from 6 to more than 1,000 ports, and manipulating electrical fields inside the device lets uninformative high-abundance ions leave, which boosts sensitivity. Indiana University chemist David Clemmer, who was not involved, said researchers would have a "chance for true discovery" because they would not have to select what to study.

The two approaches work in very different ways, but they share a direction: collect broadly first and sort it out computationally afterward. That comparison tests the case for Q-2DMS. Taking in more signal is only useful if the decoding is reliable and the output is something an analyst can act on.

The contrast is also one of maturity. MultiQ-IT redesigns the trap itself and is still a prototype whose data handling has yet to be worked out. Q-2DMS keeps a commercial Q-TOF and changes how parentage is recovered, with the decoding already producing readouts in a familiar MS/MS format. For a lab manager, that suggests one is a research direction to follow and the other is something a lab could evaluate on hardware it already owns.

O'Connor, the paper's senior author and a professor of chemistry at Warwick, told SelectScience that the team's real interest lies in what wider access might turn up that nobody went looking for. He said the unknowns are what excite the group most. The first real test of that will come when labs outside Warwick publish Q-2DMS results on PFAS screens, metabolite work or impurity profiles, and say whether the tenfold gain on near-isobaric compounds holds up on their own samples.