Chapter 1 Overview; About The Micromass Zq Detector - Waters Micromass ZQ 2000 Operator's Manual

Chapter 1
Overview
This chapter describes the Waters

1.1 About the Micromass ZQ Detector

The ZQ Detector is a quadrupole mass analyser that can determine the mass-to-charge
ratio (m/z) of diverse analytes. An HPLC system, or syringe pump, delivers liquid sample
to the instrument's analyser source. There the sample molecules ionize by means of one
of two ionization modes: electrospray (ESI) or atmospheric pressure chemical ionization
(APCI). In ESI mode, sample molecules ionize in solution before they reach the source.
On entering the evacuated source, they begin a desolvation process. In APCI mode, an
electrical discharge inside the source ionizes the sample molecules whereupon they
undergo desolvation.
The ions ultimately reach the quadrupole, which separates them according to their
mass-to-charge ratios. A photomultiplier then detects the mass-separated ions, amplifies
their signals, and sends the mass information to the data system.
Probes
An electrospray ionization (ESI) probe or an atmospheric pressure chemical ionization
(APCI) probe introduces the sample to the ion source.
Sample Inlet
Either of two methods deliver solvent and sample to the installed probe:
• An HPLC system – Delivers the eluent from an HPLC analysis.
• A built-in syringe pump – Delivers standard solutions or infusions of unknown
samples.
Vacuum System
An external rotary (roughing) pump and an internal split flow turbomolecular pump
combine to create the source vacuum. The turbomolecular pump evacuates the analyser
and ion transfer region.
Vacuum leaks and electrical or vacuum pump failures cause vacuum loss, which
protective interlocks guard against. The system monitors turbomolecular pump speed and
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Micromass ZQ™ Detector, its features and options.
About the Micromass ZQ Detector
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