GC/APCI Source High Resolution TOF-MS on GC0 pages

31-52 LCE AppsBook July08

16/6/08

15:47

Page 34

General

New Generation of GC/High Resolution
TOF-MS: APCI/APLI Source for Increased
Flexibility
Thomas Arthen-Engeland and Ralf Dunsbach, Bruker Daltonik GmbH, Bremen, Germany.

A new APCI/APLI source enables a high resolution TOF-MS to be coupled on LC and GC, thus increasing
flexibility and performance of TOF-MS in combination with GC.

TOF mass spectrometers have been widely used in combination
with liquid chromatography. These systems can demonstrate a
mass resolution of Ͼ15000 FWHM and a mass accuracy of
Ͻ2 ppm. TOF systems that are designed to work with gas
chromatography usually demonstrate a reduced performance. To
date, a solution that uses the same TOF-MS on both GC and LC
systems, merely by exchanging the chromatographic system, has
not existed. Now, the newly developed Bruker Daltonics APCI
source allows a micrOTOF, which is basically an LC–TOF-MS, to be
coupled with a gas chromatograph. The performance of the
micrOTOF, in terms of mass resolution and mass accuracy, is not
influenced by the chromatographic system used for separation.
Atmospheric pressure laser ionization (APLI) has been
described recently as a useful alternative ionization method for
certain applications where high selectivity and sensitivity is
required.1 APLI can also be realized with the new Bruker
Daltonics source.

Figure 2: hrEIC of 28 pesticides, mass window: 0.002 Da.
1.2
1.0

Intensity ϫ10 5

Introduction

0.8
0.6
0.4
0.2
0.0

6

7

8

10
11
Time (min)

9

GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH2CL2.d: EIC 216 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH2CL2.d: EIC 214 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH2CL2.d: EIC 172 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH CL .d: EIC 188 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH2CL2.d: EIC 174 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH CL .d: EIC 165 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH CL .d: EIC 249 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH CL .d: EIC 222 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH CL .d: EIC 284 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH CL .d: EIC 242 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH CL .d: EIC 180 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH CL .d: EIC 203 ϩAll MS

12

13

14

GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH CL .d: EIC 291 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH2CL2.d: EIC 213 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH CL .d: EIC 241 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH2CL2.d: EIC 146 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH CL .d: EIC 233 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH2CL2.d: EIC 207 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH CL .d: EIC 278 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH CL .d: EIC 259 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH CL .d: EIC 215 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH CL .d: EIC 230 ϩAll MS
GC–APCI 08 Pestizid Mix 40 ␮g pro L in CH CL .d: EIC 202 ϩAll MS

Apparatus
The main handicap when using an LC–MS with a GC is the fact
that LC mass spectrometers use atmospheric pressure ionization
whereas the ionization in GC–MS systems is usually realized in a
vacuum. Nevertheless it has already been demonstrated that
atmospheric pressure ionization has certain advantages over
vacuum ionization even in combination with GC.2

Figure 3: Chromatogram of 32 alkylated PAH, measured by
APLI.
4

Figure 1: Schematic picture of the coupling GC–TOF-MS with
transfer line.
Intensity ϫ10 6

3

Corona needle
GC-separation capillary
AP ion
source

2

Glass tube

1

Stainless steel capillary, resistively
heated to 320 ЊC

Thermocouple

0

GC-oven

34

0

10

20

30
Time (min)

40

50

APLI27Febr000001.d: BPC49.009–500.994 ϩAll MS. –Spectral Bkgrnd

THEAPPLICATIONSBOOK July 2008