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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