1
Introduction
What Types of Experiments Can I Perform with the LTQ XL MS Detector?
20
LTQ XL Getting Started
Thermo Electron Corporation
even need to specify a parent ion. The LTQ XL MS detector can then collect
full scan MS data, pick the most intense parent ion in the spectrum, and
fragment the ion to generate product ions.
A Data-Dependent Triple-Play experiment is the same as Data-Dependent
MS/MS, but includes the identification of the charge state of the parent
with the LTQ XL ZoomScan feature. A Data-Dependent Triple-Play
experiment collects full scan MS data, and then uses ZoomScan to
determine the charge state of the parent ion and calculate the molecular
mass. The parent ion is then fragmented into product ions (MS/MS). For
example, if the LTQ XL MS detector determines a charge state equal to 2,
and if the mass-to-charge ratio of the parent ion is
m/z
500, then the
mass-to-charge ratios of the product ions can be up to
m/z
1000 (or 2
×
500).
Use a data-dependent experiment (from templates in Instrument Setup) to
do the following:
• Identify low-level impurities in high-purity compounds
(Data-Dependent MS/MS)
• Identify metabolites in a complex mixture (Chromatographic Separation
with Data-Dependent MS/MS)
• Build a custom library of composite MS
n
spectra (Ion Tree)
You can use a Data-Dependent MS
n
experiment to identify process
impurities. In the quality assurance process for aspirin, for example, the
LTQ XL MS detector can identify impurities of less than 0.1%.
A Data-Dependent MS/MS experiment of a complex mixture of drug
metabolites can provide highly specific structural information.
Characteristic masses along the metabolic pathways of a drug, for example,
can produce MS/MS spectra that are specific to the structure of the drug.
These spectra are essential in metabolite identification.
A data-dependent experiment can produce a composite spectrum of, for
example, MS2, MS3, and MS4 data. The LTQ XL MS detector can store
the MS
n
fingerprint data in a custom MS
n
library spectrum. The data is
valuable for use in process control, quality assurance, or research.
Ion Mapping Experiments
An Ion Mapping experiment is best used to get full structural
characterization of unknown molecules in complex mixtures. In an Ion
Mapping experiment, you can get product ion scans on every parent ion
over a specified mass range. An Ion Mapping experiment can help to