

2
A Strategy for an Unknown Screening Approach on Environmental Samples using HRAM Mass Spectrometry
Overview
Purpose:
Run a General Unknown Screening approach
in an automated fashion.
Methods:
Surface water samples form the city of Berlin,
Germany were analyzed in full scan / AIF mode with a
Thermo Scientific™ Exactive Plus™ mass spectrometer
and analyzed in a widely automated workflow using
Thermo Scientific TraceFinder™ and Thermo Scientific
SIEVE™ software.
Results:
Differences in the load of contaminants could be
easily determined in the different samples; Easy detection
and identification of a significant number of contaminants
could be achieved.
Introduction
The analysis of food and environmental samples for
contaminants by LC-MS has become a quick and cost
effective routine application when run in a targeted
fashion, but this way it disregards events or
circumstances not taken into account beforehand. Run in
a non-targeted fashion, it is known to be laborious and
time consuming, making it everything but a routine
application. New generation software now links in
quantitative and (unknown) screening approaches to one
smoothly integrated workflow, tying together component
detection capabilities of unknown screening workflows
with the identification capabilities of targeted screening
and quantification software. Here we show how one data
set can serve for routine high throughput quantitative
analysis and for versatile non-targeted investigations in a
highly automated manner.
Methods
Sample Preparation
Four samples of surface water from different sources
were taken and analyzed without any further treatment. In
addition, one neat standard as control sample and one
tap water sample as reference sample were run in the
same sequence.
FIGURE 1. Schematics of the EQuan online SPE and
separation system.
6-Port
Valve
Large
Volume
Sample
Loop
Conventional
Volume
Accela1250 pump
Autosampler
Accela600
pump
6-Port
Valv
Results
Suspect Screening
The more simple way
using a large list of c
sample. It avoids the
component detection,
standards which coul
valid retention time, i
built-in database with
containing name, ele
information. Addition
containing roughly 40
inside the application
fragment search and
result confirmation (s
FIGURE 3. Suspect
As to be expected, it
number of contamina
confirming points. On
screening did not cov
visible from the neat
screening on these s
batch. A clear benefit
fragment information
additional confirmatio
In addition, a larger d
applied still left open
found because they
FIGURE 4. Three st
screen: isotope patt
library search; A: is
fragment overlay; C