World’s first mass spectrometer detects uranium and plutonium isotopes at once

Researchers in the US have unveiled the world’s first mass spectrometer that can measure all uranium and plutonium simultaneously at extremely low levels, and potentially uncover hidden nuclear threats.

The first-of-its-kind instrument, also known as Sapphire 1700, was installed at the Pacific Northwest National Laboratory (PNNL) in 2025. It was made together with Wales-based manufacturer Nu Instruments, and has 22 detectors, among which 12 ion-counting detectors.

It is the only spectrometer in the world which is capable of measuring all uranium and plutonium isotopes at once. Additionally, it has nearly halved nuclear material analysis times while maintaining accurate results.

“We’ve only scratched the surface of what we can really do with this instrument,” Megan Nims, PhD, a chemist at PNNL, noted. “As we push to overcome some of these challenges, we’re only seeing the beginning of what’s possible.” Sapphire 1700 also supports the International Atomic Energy Agency (IAEA) in identifying potential misuse of nuclear materials and technologies.

Faster nuclear detection

Mass spectrometers identify substances by measuring the mass-to-charge ratios of small particles. Widely used in medicine, food safety, as well as environmental testing, they can struggle to detect small amounts of nuclear materials, especially when isotopes must be measured separately.

To address this, the PNNL team fitted the Sapphire 1700 with significantly more detectors than similar instruments. Its custom design enables the simultaneous measurement of uranium and plutonium isotopes. It also removed interference that could affect the accuracy of the measurements.

According to the team, the technology has delivered promising results following extensive testing and daily calibrations. “It’s not trivial to calibrate an instrument like this,” Tyler Schlieder, PhD, a PNNL chemist, said. “Since it’s been in operation, we’ve completed validation of 110 measurements in just over three months.”

Schlieder shared that the machine nearly halves analysis time without sacrificing accuracy. “It’s even more amazing when you realize there’s no instrument in the world that can do this,” he continued.

Boosting nuclear safeguards

That said, faster analysis is just one benefit. The machine could also boost global nuclear security. PNNL is one of 17 laboratories in the IAEA’s network that tests environmental samples for signs of secret nuclear activity.

By spotting traces of uranium and plutonium, the instrument could make it easier to detect signs of nuclear material misuse. The researchers also expect demand for environmental sample analysis to increase as modular nuclear technologies become more widespread.

In July 2026, Schlieder presented the instrument at the Goldschmidt Conference, and it was selected for a keynote presentation. The research team aims to explore more uses for the technology and develop methods other labs could adopt.

“A lot of capabilities that the instrument comes with we haven’t been able to characterize yet,” Schlieder concluded in a press release. “As we start playing around with more of the instruments, one thing that we’ve kept in mind is that we’re ideally developing something that could be implemented elsewhere, making the benefit more widespread.”

The project was backed by the National Nuclear Security Administration. At the same time, the US Department of State funded the instrument’s acquisition.