©2017 Waters Corporation

ACOUSTIC MIST IONISATION MASS SPECTROMETERY – ULTRA HIGH THROUGHPUT ANALYSIS ON THE XEVO G2-XS

Time102.50 105.00 107.50 110.00 112.50 115.00 117.50 120.00 122.50 125.00 127.50 130.00 132.50 135.00 137.50 140.00 142.50 145.00 147.50 150.00 152.50 155.00 157.50 160.00 162.50 165.00 167.50 170.00 172.50 175.00

%

3

Time5.70 5.80 5.90 6.00 6.10 6.20 6.30 6.40 6.50 6.60 6.70 6.80 6.90 7.00 7.10 7.20 7.30 7.40 7.50 7.60 7.70 7.80 7.90 8.00 8.10 8.20

%

0

100

Time6.65 6.66 6.67 6.68 6.69 6.70 6.71 6.72 6.73 6.74 6.75 6.76 6.77 6.78 6.79 6.80 6.81 6.82 6.83 6.84 6.85

%

3

m/z500 505 510 515 520 525 530 535 540 545 550 555 560 565 570 575 580 585 590 595 600 605 610 615 620 625 630 635 640 645 650

%

0

100601.51

559.50

544.49

623.50

In 2012 Waters embarked upon a collaboration with Labcyte and AstraZeneca to explore the poten-

tial for using acoustic mist ejection as a means of introducing ions to a mass spectrometer. The tech-

nology has numerous desirable features including:

Extremely rapid sampling times, up to three samples per second

Automated handling of samples, from storage to delivery to the mass spectrometer

No contact between samples and zero crosstalk

Low sample consumption, allowing repeated sampling from the same well hundreds of times

The project has now progressed to running real assays across three AstraZeneca sites, with multimil-

lion compound screens being run in a matter of weeks, an order of magnitude faster than previously

possible and at a fraction of the cost.

The Xevo G2-XS QToF is a natural fit for this technology. The combination of high resolution, mass

accuracy, speed and sensitivity allow sample analysis to be reliably performed in time frames which

take advantage of this ultra high throughput ionisation source.

The Waters research Xevo G2-XS with acoustic source in

Wilmslow (UK)

The sampling nozzle is held at a high voltage and causes

charge separation in the well. The ultrasonic transducer of the

Echo is used to spray a mist of charged droplets out of the

well which are transported to the mass spectrometer

A modified Echo 550 Liquid Handling system is used

to spray a fine mist of droplets directly out a 384 well

polypropylene plate. A sampling nozzle is suspended

directly above the well with a high voltage applied of

the opposite polarity to the ionisation mode. This

causes charge separation within the well such that the

ejected mist contains charged droplets of the desired

polarity. These desolvate as they are transported

through an interface and into the mass spectrometer.

The Acoustic Mist Ionisation MS source is designed to

be an option for the Xevo G2-XS, compatible with

Universal Ion Source architecture of Waters’ mass

spectrometers. This addition to the source options of

the mass spectrometer is a powerful new technique,

allowing ultra high throughput analysis. In its current

form the system is capable of running over 100,000

samples a day, with scope for yet further optimisation.

Automation plays an indispensible role in taking

advantage of this extremely fast sampling technique.

AstraZeneca are now using a Labcyte Access

Laboratory Workstation, capable of automatically

loading and processing batches of 150 x 384 well

plates, 57600 samples in total which typically takes

ten hours to analyse.

A key part of the project has been developing

software which allows the association of plate

barcodes and well coordinates with the scan numbers

of the data being acquired. The application that has

been developed runs on the MassLynx host PC and

communicates with both the mass spectrometer and

the Echo control PC. When an ejection from the Echo

is reported, the barcode and well coordinates are

stored in a log file along with the current scan number

from the mass spectrometer. This file is then used by

a second data parsing package which interrogates the

MassLynx data file and combines the scans pertaining

to each ejection, to produce a single spectrum per

sample.

Over half a million samples were analysed in one week, or

1380 x 384 well plates

8 full plates in about half an hour

One 384 well plate every 4 minutes

One sample every 300ms

“The acoustic mass spec project that we’re working on

within AstraZeneca is really designed to enable us to

utilise mass spectrometry as an end point for high

throughput screening. We believe this gives us a higher

quality, higher throughput and lower cost option for

biochemical high throughput screening and that should

generate better starting points for our drug discovery

projects moving forwards.”

Jonathan Wingfield

Principal Scientist, Screening

Sciences and Sample Management, AstraZeneca

Source: Select Science

“The long term benefits of this technology will be a

significant reduction in assay development cycle times, a

huge reduction in the costs of assay development and the

costs of screening. We estimate those to be in the order of

100 to 1000 fold reduction in cost, and most importantly,

an increase in the quality of the data that we see coming

out of these assays. But anywhere in the industry that

we’re measuring metabolites/analytes in low volume, this

technology could potentially have a huge impact.”

Steve Rees

Vice President, Screening Sciences And Sample Management,

AstraZeneca

Source: Select Science

Authors 1Rhys Jones, 1Emmy Hoyes, 1Ed Sprake, 2Phil DeLand, 2Luke Ghislain, 2Eric Hall, 2Sammy Datwani, 3bIan Sinclair, 3bMartin Bachmann, 3aJon Wingfield Affiliations 1Waters Corp., Wilmslow, UK, 2Labcyte Inc., San Jose, CA, USA , 3aAstraZeneca, Cambridge, UK, 3bAstraZeneca, Alderley Park, UK,

In addition to ultra high throughput screening, this

technology has shown significant advantages for

assay development, reducing development times

from, typically, 6 months to around 2 weeks. As the

wells can be repeatedly sampled hundreds of times it

is possible to perform kinetic studies under a wide

range of conditions, such as enzyme and buffer

concentrations.

Other applications areas, including lipidomics and

synthetic biology are being explored to see if they can

take advantage of this technology. Early results are

promising.

Spectrum produced for each sample