Building a better mass trap

New technology may change the way common laboratory machine, the mass spectrometer, is made

By David Braker

The new mass spectrometer is more accurate and efficient than current models because it can detect all atomic and molecular components at once. Most other mass spectrometers examine only one component at a time, making them slower, less efficient and more prone to error.

“While it’s still a work in progress, this new mass spec may eventually touch a lot of fields,” said Gary Hieftje, IU Distinguished Professor of Chemistry. “It promises better estimation of the concentrations of pollutants, better medical and forensic diagnoses, less expensive clinical analyses and rapid progress in bioscience. Basically, this is a tool that could be extremely important in improving analyses wherever mass spectrometry is used.”

Hieftje, with graduate student James Barnes IV, shop personnel and other students, built the new instrument from scratch in his lab and the workshop at the IU Bloomington Department of Chemistry.

The first application of the new spectrometer takes advantage of the fourth, super-hot state of matter, called a plasma, to increase the measurement sensitivity of the device, as reported in last week’s Analytical Chemistry, an American Chemical Society journal. The scientists say the new device, which analyzes samples quickly, may ultimately be cheaper to produce than other mass spectrometers on the market.

Mass spectrometers, as much a fixture in scientific labs as microwave ovens are in kitchens, work by charging particles in a sample and determining the weight of the particles. Because every element and molecule possesses a unique set of masses (weights) when charged, the mass spectrometer can identify the tiny particles and determine their concentrations in a sample.

The research team compared their new device, which combines a Mattauch-Herzog geometry mass spectrograph and a multi-channel focal plane camera, with the most commonly used mass spectrometers in the world’s scientific labs. The IU scientists found that their prototype detected sample ions with greater accuracy, precision and sensitivity, even though the present prototype has only a limited number of channels.

Researchers from Pacific Northwest National Laboratory, the University of Arizona and Steward Observatory also contributed to the report. The spectrometer was developed and tested using funds from the U.S. Department of Energy’s Office of Non-Proliferation Research and Engineering at Pacific Northwest National Laboratory.