1 Introduction
Why Use the Surveyor MSQ Plus MS Detector?
2Surveyor MSQ Plus Getting Started Thermo Scientific
An MS detector consists of an ion source, a mass analyzer, a vacuum system, and an ion
detector. The ion source performs four functions: it separates the analytes from the solvent
molecules; it ionizes the analytes; it drives the ionized solutes from the liquid phase to the gas
phase; and it provides efficient transfer of the ions to the mass analyzer. The vacuum system
provides the driving force for drawing ions into the mass analyzer and the environment in
which the ions can reach the detector without colliding with other gaseous molecules. The
mass analyzer produces an electric field or a magnetic field or both that allow only ions within
a specified mass-to-charge range to reach the ion detector. The ion detector detects the
presence of ions as they exit the mass analyzer.
The Surveyor MSQ Plus MS detector performs two types of complementary atmospheric
pressure ionization: electrospray ionization (ESI) and atmospheric pressure chemical
ionization (APCI) and uses a transfer lens to transmit ions to the mass analyzer. The mass
analyzer consists of a single round quadrupole with an upper mass range limit of 2000 u at
unit resolution. The vacuum system consists of an external forepump and an internal
turbomolecular pump. The external forepump operates from atmospheric pressure down to
10-3 Torr and handles high gas loads of approximately 30 m3/h at 1 Torr. The internal
turbomolecular pump provides a high vacuum of 10-6 Torr. The ion detector is a conversion
dynode, which allows a time interval of 200 milliseconds for switching between the positive
and negative polarity modes.
The Surveyor MSQ Plus MS detector measures only 30 cm (12-in.) wide and integrates
seamlessly with the Surveyor LC system. The new innovations for this MS detector that make
it ideal for the chromatographer include:
• ESI and APCI FastLoc™ Probes, allowing you to switch between the two ionization
modes in less than a minute
• Wipe-clean, M-Path™ ion source with a patented cone wash system for ultra-rugged
performance with non-volatile phosphate buffers
•Automated Full System Autotune
• Interactive method setup with 10 built-in editable templates
The M-path source and the cone wash system allow you to use mobile phases that would
ordinarily be prohibited because of their tendency to clog the entrance cone of the ion source.
The positioning of the probe insert directs non-volatile components, such as those from
mobile phase buffers and ion pairing agents or sample matrices, away from the orifice of the
entrance cone. A low flow of solvent (100 to 250 μL/min) from the cone wash system
spraying the edge of the entrance orifice helps to prevent a build up of non-volatiles during an
LC/MS run.
The tuning and calibration process that is required for all quadrupole mass analyzers to
optimize their mass range, mass accuracy, and mass resolution is completely automated with
wizards. Figure 1 shows the user interface for these wizards. The service engineer tunes and
calibrates the detector at installation. Operators perform an automated mass scale calibration
whenever they notice a drift in the accuracy of the reported masses of their known standards.