Fast atom bombardment of molecules in the gaseous state

Journal of Mass Spectrometry and Zon Physics, 46 (1983) 399-402 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands

Znternalional

FAST

B.

ATOM

BOMBARDMENT

KRALJ,

“Jotef

V.

KRAMER

Stefan”

Institute,

OF

and

MOLECULES

IN

GASEOUS

STATE

VR&?AJ

V.

Kardelj” University

“E.

THE

399

of

Ljubljana,

Jamova

39,

61000

Ljubtjana

(Yugoslavia)

ABSTRACT lnvolatite (M -

HI-

molecules

species

evaporates

it

bardment

may

mass

electron

in

usually

negative

be

ionized

spectra

impact

of

exhibit

ion

a protonated

fast

by

atom

fast

some

atom

volatile

molecular

bombardment impact

in

compounds

ion

mass the

are

MH+

in

spectra.

gaseous

If

state.

compared

to

positive

and

an

a compound

Fast

those

atom

bom-

obtained

by

ionization_

INTRODUCTION Since mass

the

first

spectrometry

ionization

of

negative

and

polar

Such

the

on

sample

tated

tip

spectra

ions,

from

formed

by

Here

the

sample

state.

found,

gaseous various

hexene

mass

gaseous

are

at

the

results

least

rise

appearance

from

kind

of

and

ortho

we and

of

spectra

if

also

at

all,

ionize ion

to

meta

present

argon

mass

or

FAB

spectra.

more

dihydroxybenzenes

atoms

onto

facili-

MH+

liquid

and These

sample

expect in

fragment

toluene, in

molecu-

is greatly

could

by

FAB

the

high

be deduced.

solid

and

both

abundant

we

of

in

2).

can

the

naphthatene,

want

(ref.

compound

mass

fast

ionization

highly

in

of

relatively of

(FAB)

advantages

spectra of

is used

place

negative

as benzene,

Here

the

is ionized,

compounds

positive

such

of

mass

that

glycerol

taking

and

many

to

weight

the

a beam

shows

by

bombardment

confirm

of

in

the

atom

compounds

impact

Experience

fast

FAB

from

sample

what

partially,

that

studies

by

reaction

as to

progesterone.

obtained

the

molecular

compounds

and

published these

probe.

transfer

all,

of

obtained

of

arises

of

applicability

mainly

characterised

which

giving

of

spectra

usually

a metat

are

In

reported,

suspension

first

the

compounds. were

question

on

subsequently

a proton

phase,

types

1981

all

of

or

evaporates,

We

qu inone, FAB

the

mass

matrix.

on

spectra

FAB

are

I),

ions

a solution

(M-H)-

in

organic

if

ions

the

(ref.

positive

tar weight.

the

report

when

the

gaseous

by

FAB

This

was

proved

nitrobenzene, detail and

in

anthra-

results

showing

nitrophenols

in

the

state.

EXPERIMENTAL Mass recording

spectra metastabte

were ion

0020-7381/83/0000-0000/$03.00

obtained

on

a CEC

decompositions

0

in

21--1lOC the

field

mass free

spectrometer regions

(MIKES)

with

the

(ref.

1983 Elsevier Scientific Publishing Company

3).

facility Fast

for

400

argon

atoms

source

of

based

laboratory, and

on

the

chamber fast

at

90°

(ii)

{iii),

not

of

neutralization

size

of

the The

5).

optical

axis

of

possible

our

fast

mass of

by

a modified

(ref.

4).

of

Ar+

atom

beam

the

presence

sttidy

by

ion

mass

much

to

A

produced

was

spectrometer.

to

The were

mass

spectra

easily

into

the

intensity

yet

in

our

electrons

be

actual

not

ion

made

oscillating

it

directed

ions

oscillation was

by

allowing

atoms

residual

electron

modification

gun,

of

modes were

mass

spectra

from

during

proved

compare

spectra

(El)

spectra

were

was

different

mass

impact

too

pathways

the

(ref.

above

electron

evaporate

tation

principle

housing

the

negative

FAf3

the

produced

mounted ionization of

the

estimated.

DISCUSSION

listed

and

of

of

the

intention

compounds

were

ionization

mainly

and

AND

The

and

to

energy

Penning

source

beam

RESULTS

phase,

the

reduction

ion

atom

positive.

5 keV

consisting

a suitable

inside

about

of

the

ionization.

recorded: under

(iI

the

MIKES

for

the

spectra

the

following

in

the

conditions

those the

Additionally,

from

reason

mass

pressure

matrix

measurement. the

this

FAB

identical

a sample-glycerol

using

For

obtained

as for

compounds most

gaseous

which

important

(i); do

fragmen-

method.

loo E

DH El

65

tt4+-I 139 ‘I Q

N-J

W

93

-$ 60

39

.-: 40 40 [Ar +I

BO 30

-1.:

40

60

30 m/2

100

120

I-

40

60

00 m/z

1M

120

140

40

SO

80

100

120

1,

80 E

20 t,

y-5

39

30 40

JlbL+4,‘L so

11’11. I’,

1

!

80

100

20

120

0

m/z

Fig.

1.

Positive

ion

El

m/z

and

FAB

mass

spectra

of

o-

and

m-nitrophenols

401

ion mass spectra

Positive The

main

occurrence

characteristic

of

the

fragmentation intensities for

pattern of

some

instance,

here the

their base

The

phenol.

El

Nearly

Negative Et pounds

ion and

greater

90 % ion

positive

El

mass FAB

the

similar

of by

mass rel.

FAB

the

to

mass

base

those

found

be

more

a factor

in

with

El

4

and

2,

in

to

rise

gaseous these

FAB

mass and On

, which,

in

in

is the The

general,

spectra.

the

Thus,

(M -2H)+‘,

the

turn,

but

other

hand,

in

El

an

intensity.

and

FAB all

appear

in

also

mass four

the

holds

spectra spectra

lower for

El

of

the

show

mass

introphenols

and

FAB

and mass

are

peak

identical

region

are

shown

in

intensities.

more

spectra

of

Fig.

1.

noticeable

for

m-nitro-

dihydroxybenzenes.

and

FAB

examined

negative exhibit

ion FAB

mass

spectra

differ

mass

spectra

with

markedly. the

base

Most, peak

loo El

but

not

the

molecular

in

all,

of

the ion

commass

NO?

?H

46

80

0 Cl

-Ei .60

NO2

L .

YIJ 20

20 -

60

60

100

120

140

60

80

m/2

100

120

140

m/z

100

M-. 139

OH

MY139

FAB

80T z

NO1

‘7 60?! S

40CM-HI-

20 -

46 j co

122

65 I 60

I

I 80

I,

I 100

I I I,, 120 140

40

60

m/2

Fig.

2.

In

Differences

ion mass spectra

100

5

But

(M-H)+

respectively.

is M+.

phase

spectra.

ionization.

pronounced

toluene

the

throughout

give

of of

spectra

peak

naphthalene

spectrum

region

same

to

tend

spectra

FAB

ion

is also

ions

FAB are

about

molecutar

between

fragment El,

in the

has

positive

which

is quite

intensities peak

spectrum

the

like

of

ion,

M+’

Negative

ion

El

II0

100 m/z

and

FAB

mass

spectra

of

o-

and

m-nitrophenols

120

140

402

region

at

WI-’

mass

spectra

intensities spectra The

these mass

(M-H}-

in from

FAB

that

of

ions

in

the

Fig.

are

intense

spectra in

negative

ion

the

in

mass

gas

The

most

abundance

marked

This

of

difference

feature

are

here

above

place.

almost

(M-H)-

is seen

is clearly

different ion

in

if

expressed

are

El

the

in

the

mass

be

if

HI-,

a glycerol

with

Both

modes

representing

of

the

base

absent. matrix

molecular

observed

Otherwise,

should

in

protonated

behaviour.

IM -

completely

compounds A

spectra

phase

completely

pseudomolecular

literature.

took

the

show

the

the

matrix

ionization

ions

from

findings

. The

M-.

considered.

electron

M-’

(M-H)-.

2.

even

spectra.

previous

weakly

dihydroxybenzenes

produce

in

zation

exceeds

fragment

isomeric

FAf3 the

the

nitrophenols

ionization -peak

a relatively

always

of of

and

ion

high

a compound

are

MHf

consistent

in

positive

intensities,

but

evaporates

from

with and

only

if

the

ioni-

matrix,

considered.

ACKNOWLEDGEMENT We

thank

the

Research

R.S.

Bordoli,

Community

of

Slovenia

for

financial

support.

REFERENCES 1

M.

2

D.H.

Barber,

(1981)

3

V.

4

J.D.

5

V.

(1981) Vrtiaj,

Mass

Sedgwick

and

A.N.

Tyler,

J. Chem.

Sec.,

Chern.

Commun.,

J. Am.

Chem.

325-327. Williams,

103

A.D.

C.

V.

Spectrom. Gow

VrBEaj,

Bradley,

G.

Bojasen,

S.

Santikarn

Kralj,

M.

33

(1980)

Jr.,

,Rev. Sci. jnstr.,

and

L.C.E.

Taylor,

Sot.,

5700-5704.

and B.

Kramer, Ion J.S. Kralj

B. Phys.,

Foster, and

V.

Kramer,

Medved,

J.

Marsel,

J.H.

Beynon

409-416.

To

be

24

(1953)

published

696-608.

elsewhere.

and

T.

Ast,

Int.

J.