SONARSTOP LOOKING, START SEEING
®
WHAT IS SONAR?
For busy laboratories that need to get the answer right first time, with efficient workflows, SONAR™
provides new possibilities. It is an acquisition mode that collects MS/MS results from a Data
Independent Acquisition (DIA) experiment on selected Waters® QTof instruments. This is achieved
by sliding a resolving quadrupole window over a specified mass range during an MS scan,
giving increased selectivity compared to a conventional DIA experiment.
BENEFITS OF SONAR
Accurately and reliably quantify your analytes with
SONAR, which has scan rates compatible with UPLC speed
separations. In this peptide analysis the chromatographic
peak is well characterized producing good quantitation.
■■ Improved laboratory efficiency
■— Routine MS/MS spectra on every ion in your data, without method development
■— Cleaner spectra allows automated data interpretation
■— Quantify and identify from a single injection
■— Operates at UPLC® speeds
■■ Increase confidence with the right result first time
■— High selectivity improves data quality
■— Library or database searches become more reliable
THE POWER OF SELECTIVITY
Increasing selectivity leads to greater knowledge of your samples, confidence in the results, and reduces the need for time consuming repeat injections.
With SONAR this peptide data becomes much cleaner due to the increased selectivity provided by the quadrupole. Ions of interest are now much easier to identify. For any sample type, library or database searches become more reliable, improving compound identification.
WITH SONARWITHOUT SONAR
DATA INDEPENDENT ACQUISITIONS
Conventional DIAIn order to understand SONAR, let’s start with conventional DIA experiments. Ions that are generated in the source pass through the quadrupole, collision cell, and onto the ToF with no discrimination before being recorded by the detector. During the analysis, the collision cell alternates from high to low energy from scan to scan. The energy switching is synchronized with the data acquisition producing two data channels, one for high energy and one for low energy.
Without intelligent data processing, the spectra would be very complicated. Software, such as MSE data viewer and UNIFI,® aligns the two data channels automatically. This makes it possible to assign fragments to their originating precursor ion, even when there is some overlap with chromatographic peaks. For co-eluting peaks or applications that don’t have narrow peak shapes, this approach begins to struggle, since it becomes increasingly difficult to automatically assign fragment spectra to the correct precursor ion.
PRECURSOR IONS
FRAGMENT IONS
A1 B1
B1
A2 B2
Inte
nsity
Inte
nsity
Retention Time (min)
Retention Time (min)
A2 B2
B1
DIA software associates precursor and fragment ions using their chromatographic
peak profiles.
Source Quad Collision Cell Low CE High CE
TOF Detector
TIC of precursor
TIC of product
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SONARRoutine MS/MS data is available without the need for time consuming method development, or the risk of missing information by using data dependent options. The main difference between DIA and SONAR is the behavior of the quadrupole. Instead of remaining open and transmitting all ions, it slides over the selected mass range increasing selectivity while still operating at UPLC speeds. Each scan is made up of 200 spectra. Filtering of the precursor ions by the quadrupole increases the selectivity of the method.
The resolving quadrupole creates an extra dimension to the data. Compounds that are chromatographically co-eluting are now separated and recorded individually, and library searches are more reliable. SONAR provides data for quantitation and identification in a single injection.
Collisionenergy
Quadmass
Scans0 1 2 3 4
1
200
Datachannel 1 2 21
Spectra
During each scan the quadrupole separates co-eluting precursor masses by scanning the mass range, and transiting them in sequence. Fragment ions from different precursors can then be recorded separately and assigned with confidence.
m/z
Precursormass
Quadrupoletransmissionwindow
High energy
ion
inte
nsity
m/z
Ion
inte
nsity
m/z
Instrument operation; collision energy is applied to alternate scans while the quadrupole scans the precursor mass range. 200 spectra per scan are acquired allowing the fragment ions to be detected and recorded separately.
Waters, The Science of What’s Possible, Xevo, UPLC, and UNIFI are registered trademarks of Waters Corporation. SONAR is a trademark of Waters Corporation. All other trademarks are the property of their respective owners.
©2016 Waters Corporation. Printed in the U.S.A. October 2016 720005785EN LM-SIG
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www.waters.com/sonar