Chapter 2 Functional Description; Overview - Thermo Scientific LTQ Series Hardware Manual

Functional Description

Overview

Thermo Scientific
This chapter describes the principal components of the LTQ Series mass spectrometers and
their functions.
Note Unless otherwise noted:
• For the LTQ mass spectrometer, follow the LTQ XL information.
• For the LTQ Velos mass spectrometer, follow the Velos Pro information.
Contents
• Overview
• Syringe Pump
• Divert/Inject Valve
• Mass Spectrometer
Figure 1 shows a functional block diagram of an LTQ Series system that uses either a liquid
chromatograph with an autosampler or the syringe pump as the inlet. A sample transfer line
connects the LC to the mass spectrometer. The autosampler and LC are usually installed to
the left of the mass spectrometer. The divert/inject valve is integrated into the front panel of
the mass spectrometer.
In a typical analysis by LC/MS, a sample is injected onto an LC column. The sample then
separates into its various components. The components elute from the LC column and pass
into the mass spectrometer for analysis.
Upon entering the atmospheric pressure ionization (API) source, sample molecules are ionized
and desolvated into the gas phase by any of these methods:
• Electrospray ionization (ESI)
• Heated-electrospray ionization (H-ESI)
• Atmospheric pressure chemical ionization (APCI)
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