Mass spectrometry (or mass spec) is an analytical chemistry technique that helps identify the amount and type of chemicals present in a sample by measuring the mass-to-charge ratio and abundance of gas-phase ions.

As standard, mass specs have 3 components – a component to convert samples from liquid to gaseous form; a component to ionise the sample (hit with high energy to turn to positive or negative ions); and a component to detect quantities of each ion (peaks of each ion seen).

Instead of using a needle to aspirate and spray the samples as with standard mass specs, the acoustic mist ionisation mass spec (AMI-MS) sends a sonic pulse through liquid creating a ‘mountain of liquid on the surface’. For compound handling, a 2.5 nanolitre (nL) droplet is generated and fired from the liquid surface. For AMI-MS we send a second pulse through the mountain of liquid and this explodes the 2.5nL droplet into hundreds of femtolitre droplets. In effect sending a tornado of droplets through a charged field to generate a stream of ionised particles into the mass spectrometer.


10,000

Allows us to generate data at a rate of 10,000 data points per hour.

1400Hz

The acoustics fire at 1400Hz frequency (1400 times per second) – that means we fire in 1400 bursts of droplets every second.

~160

For some analytes, we only need ~160 droplet bursts from a sample to generate enough ions – delivering samples to the mass spec at a rate of 3 per second.



A scientist's perspective

Jonathan Wingfield Principal Scientist, Discovery Sciences

Why did AstraZeneca invest in this equipment?

When you see the droplets flying and you see the science behind it – it’s astonishingly cool. It’s revolutionary. It allows us to work at very high throughput and with very small sample volumes – we only need 2nL of sample. Using this screening platform we can screen more compounds or more targets for the same cost. For some assays we could reduce the cost of High Throughput Screening by 80%.

What was AstraZeneca's role in its development?

AstraZeneca has brought together a world leading supplier of mass spec technology (Waters) and the global leader in acoustic droplet ejection technology (Labcyte) to deliver this revolutionary platform. Having identified the opportunity, we took the idea to the partners, suggesting that it is possible to use acoustics in a different way in mass spectrometry. Being open about the work we are doing has shown the wider scientific community that we are prepared to invest in ground-breaking science; we are not just making a small change in mass spectrometry, but we are leading a potential revolution in mass spectrometry screening. We’re engaging the broader scientific community early in the process, and delivering real benefit to the community overall.

What was the reaction within the research community?

The AMI-MS platform won the 2015 Innovation Award from the Society for Laboratory Automation and Screening. This is awarded to the podium presentation at the annual conference that shows the most innovation and impact in screening. We are the first non-US based company to receive this award.

Where can I find more? Have you published any results of this technology?

We recently published a paper on this technology in Analytical Chemistry with our collaborators at Waters and Labcyte: https://pubs.acs.org/doi/10.1021/acs.analchem.9b00142. Allowing us to reach a throughput of 100,000 samples per day on a single mass spec, we show that this technology – due to its speed, sensitivity, simplicity, robustness and consumption of nL volumes of sample – will have a major impact across many areas of basic and applied research.