Analysis of mixtures of ionic compounds using Fast Atom Bombardment and a triple analyzer mass spectrometer

International Journal ofhfass Elsevier Scientific Publishing

Analysis

of Mixtures

Analyzer

Mass

K.B.

Tomer,

of

Crow,

Center

Lincoln,

NE

Ionic

Compounds

Using

Fast

Atom

Bombardment

and a Triple

Spectrometer

F.W.

Midwest

375

Spectrometry and Ton Physics, 46 (1983) 375-378 Company, Amsterdam - Printed in The Netherlands

and M.L.

for

Gross

Mass

Spectrometry,

University

Nebraska,

of

68588

ABSTRACT The combination of fast atom bombardment (FAB) and mass spectrometry/mass spectrometry (MS/MS) has been applied to the analysis of cyclic peptides and anionic surfactants. INTRODUCTION The

recently

itself

to

be

applicable

zwitterionic spectra

combination

chemical

spectra MS/MS

are can

can

simple

serve

from

CYCLIC

been

of

as a separation ions

some

peptides

for

by be

the

metal

however,

the

analysis other

combination using

3) for

recent

FAB.

in cases

and

a

with

and

removed

component

The of amino

are:

MS/MS; where

isolates

additional

2)

a

the

FAB

of

the

which

are

MS-I

the

1)

structural

(ref.3).

of our

anionic

and mass

or

also

for

peptides

produced

reversal

results and

is

information;

each

easily

by charge

present

of cyclic

stage

the

often,

parallel

activation

structural

are

is

shown

ionic

general,

advantages

can

and

devoid

in

offered

matrix

polar,

deprotonated,

(ref.21

cyclic

by collisional

negative we

distinct

advantages

glycerol

In

has

solvent.

developed

and

(FAB)

of

There

(MS/MS)

offers

linear

the

can be produced paper

(ref.1).

analysis

a protonated,

be produced

information analysis

spectrometry

the mobilizing

The

4)

In this

and

has

as

mixtures;

the

vaporization of

bambardment

fragmentation.

from

and

such

noise

atom

spectrometry

materials.

spectrum"

fast

largely

of the two techniques

acid-containing "mass

arising

advance

compounds

of

limited

spectrometry/mass

instrumentation

the

mass

and

background

Mass

by

the

consisting

simple, molecule

extensive

technique for

compounds

are

cationized

polar

announced

application

of FAB and MS/MS

to

compounds.

PEPTIDES

Underivatized mass

spectra

ions

which

peptides

are

of derivatized can

result

OOZO-7381/83/0000-0000/$03.00

difficult

cyclic in

peptides

incorrect Q

to

analyze are often

sequencing.

1983 Elsevier Scientific

by

mass

plagued Since

spectrometry. with

rearrangement

collision

Publishing Company

The induced

376 decomposition than the

(CID}

rearrangements, analysis

of

and sequencing

spectra

are

we have

applied

underivatized

typically

dominated

the

cyclic

combined

peptides

by simple

techniques

to

cleavages

both

molecular

weight

analysis

of

cyclic

obtain

information.

An example I@B98 *e ,e_ GB _ IB_ ,e_ lb no_ ,e_ B

of

our

results

can

be illustrated

by the

the

1 obo

560 Fig.

rather

FAD and MS/MS to

of

1. FAB Mass Spectrum

Fig.

of

2. CID Spectrum

Protonated

Ion of Cyclo-(Leu-Pro-Gly)4;

Molecular

Cyclo-(Leu-Pro-Gly)4

of the

peak b=MH-Leu-gly;

peak

a=MH-Leu;

peak

c=MH-Leu-gly-pro;

gly-Pro-gly;

peak

d=MH-Leu-

peak e=MH-(Pro-Gly-Leu)2;

peak f =MH-(Pro-Gly-Leu)2-Leu MH-(Pro-Gly-Leu)2-Leu MH-(Pro-Gly-Leu)

; peak g=

gly;

3; peak

peak h=

i=MH-(Pro-

Gly-Leu)3-Leu

cl

Y

NH-CH-COI

N +li

Y

I Leu

GUY

I

I

Pro-leu-Gly-Pro-Leu-Gly-Pro

Scheme 1.

Loss of

dodecapeptide, observed m/z Leu-,

at

Gly

-

1069

and

Pro

(see to then

co -01

Gly

I

Pro-Lsu-Gly-Pro-Leu-Gly-Pro

refers

to

loss

cyclo-(Leu-Pro-Gly)4. m/z

535 corresponding Gly,

0 HN

:H-C&CO+

CO-Gly

Fig. loss occur.

of An

1). of

COCH2NH, for intense

The first two The

y

I Y”

protonated

major

Pro-Gly-Leu CID spectrum

example.

fragment

sequences. of

the

molecular ion

is

ion

is

observed

at

Sequential protonated

loss molecular

of

377 ion

2)

(Fig.

shows

complete

successive

amjno

spectrum.

The fragmentation

proton&ion

on

the

Another was

by

patterns

the

application of

easily

can from of

the

the

major

due

peaks

in

based

cleavage

acylium

ion

FAB MS/MS to

cyclic

spectrum

assigned

on the

to peptide

acyl 1). which

The of

the

sequencing

(ref.4),

(ref.5). basis

an

(scheme

Toxin

to

on initial

form

terminus

carbonum

EI mass

definitively

the

explained

bond

Helminthosporium

using

and

comprise

-N-C=0

Ions

information.

be readily

with

initiated

analysis

sequence

CO losses)

nitrogen

incorrectly

was

acid

(and/or

then

of

the

sequenced

sequence

is

example

provided

losses prolyl

Fragmentation

ion. is

acid

amino

the

correct

FAB/MS/MS

results. Thus, to

the

application

provide

1 ittle

molecular

or

no

more cyclic ANIONIC

weight

interference

peptides

and

from

to

relatively

phosphates

Fig.

FAB/MS/MS to

test

the

analysis

straightforward

rearrangement

the

genera?ity

of

cyclic

sequencing processes.

of

these

peptides information

We are

and

,

.

3A.

.

simple phosphonates,

.

Negative

.

.

sb‘.

Ion

anionic are

organic difficult

of

compounds to

-

CID Spectrum

n/2

acid.

with

investigating

results.

the

analyze

rdo M-H Anion

of

such due

as to

su 1fonates, problems

1.30 Benzenephosphonic

acid.

Fig.

appears

COMPOUNDS

Some

.

of

36.

Charge

Reversal

51

Spectrum

of the

M-l Anion of Benzenephosphonic

in

378 removing

them from

(ref.6)

have

utilized

field

sulfonated

surfactants

FAB/MS/MS,

we have

the

combination

information CID

(see

Figure

m/z These

ions

the

is the

indicate

negative

ion

Similar

anion

of

reversal m/z

the

MS/MS to ion

anionic

and charge

analyze

reversal

et.

al.

a group

spectra.

surfactants

of

Utilizing

and found

that

CID provide

structural

acid.

The negative

bemzenephosphonic

shows

only

ions

spectrum

(Fig.

51 and

presence

the

provides

of

39.

the

information

due

An m/z aromatic

to

loss

3B) shows 39 ion

of the

is

ring.

the

carbon

with

m-benzenedisulfanic

major

also

Thus,

about

H and HP03-

skeleton

ion

at

observed. the

charge

missing

in

CID spectrum.

results

have

benzenephosphorous

acid

from

of

the

analysis

M-H at

with

Weber,

mode alone.

the

signals

spectrum

CID

GC analysis.

negative

any

some simple

The .charge

other

show

either

for

combined

not

ion

from

of

3A).

77 with

reversal

negative

example

spectrum

did

investigated

of

them

desorption

but

unavailable

A typical ion

and derivatizing

water

two types

been

observed

verifying

negative

the ion

complementary

nature

acid

of

the

and

information

spectra.

ACKNOWLEDGEMENT This

work

was

Science

National

supported

Foundation

by

the

Regional

Midwest

Center

Instrumentation

for

Mass

Spectrometry,

Faci 1 ity

(Grant

a

#CHE

78-18572). REFERENCES 1 2

3 4 5 6

and J.-C. Rousten, C.R. Acad. SC. Paris, Ser 8, 283, a) F.M. Devienne, 397-399 (1976); b) M. Barb,er. R.S. Bordeli, R.D. Sedgwick, and A.N. Tyler, J. Chem. Sot., Chem. Commun., (1981) 325. R.G. Cooks, and G.L. Glish, Chem. and Eng. News, (1981) .54, (48) 40-52. J.H. Bowie, and T. Blumenthal, J. Am. Chem. Sot., (1975) 97, 2959-2962. M.L. Gross, D. McCrery, F. Crow, K-B. Tamer, M.R. Pope, L.M. Ciufetti, H-W. Knoche. J.M. Daly, and L.D. Dwnkle, Tetrahedron Letters, submitted. G.D. Staffeld, M-S. Anderson, D. J. Weber, and R.P. J.M. Glish, C.C. Swceley, Scheffer. Tetrahedron Letters, 38, (1982) 45. CRheFber, K. tcvsen, G.J. Louter, A.J. Nenk Boerboom, and J. Haverkantp, Anal. -9

54

(1982)

1458-1466.