Mass analyzers

Mass analyzers : Quadrupole mass analyzer, time of flight mass analyzer, fourier transform ion cyclotron resonance(FT-ICR), ion trap mass analyzer(3D ion trap and 2D ion trap), orbitrap mass analyzer.

1. Mass Analyzers
_Suadrupole Mass Syedluometos

A quadropsle mau Alte consists 6f 4
asolte) “metal vods.. .

a opposite weds have an applied potential
(Wav costa) and the other 2 vds have
a potential 4 - (urvoswd) ıwhae U tsa
de voltage and Vvtos(wt) ïs an ac voltage.

an nie voltages affect The trajectory
d fons braveling don the light par
centered between the 4 oda +

For given de x ac voltages » only ins of
mos lo change vatio pas, Thacugh

a catain
the voltages on the

fhe quadmpele lta os
wods ave verted.

There ave two methods : magia war
holding Ur V constant ov varying Us vom
Ained Au a constant uw

uadvupale Ms conde of an fon source,
ion ops b acceleroke and pus le tens
lamen an aperture ints the quadrupole

ten y the quémupole ta sell with
consi voltage supplies an exit apahıre, an
ion detector, detection elchmice and a

High vacaum system.

2. By poa selection $ Fee can
“frequency, an io $ the desiaed m an
made to pais thaough the sele while
unwanted masses will ber callected son ong

Ma eledso
4 oe © thes’ ratio viv, the stable
tolewal whith. comresponds bo 0 stable mas,
fnlaual is veduced, so thot only Tons
one mas Can pas the quadruple le.

When the value of 4 ts Kepl contas
eae A Kal
value of v

mr es
en Req?
à k= constant
Rs vod tus of eled ie field
one rate
sent st
an“

3. Working.

Tons om the fon sousce will make thes
way to the quadruple mass fille and dina
ooh the Jed : 4 Fly

The main Aundims of AMA is te separate
the potides based on miz ratio

Nowra mixture’ of (ons comes om the
{on source

This mixture will have +ve,-ve, small
and Aonge pakde. | :

For instant let us consider the pad of,
ave electrodes 1%

Now lel us consider the ve charged
guides ae approaching the Ave ae

iS tet us now consider the lange size
qukde y
A ave pc. ment fs applied to the
pa electrodes.
when wa approach the +ve electrode ,
elled + > :
‘a as make the way out of the

fills This ie ask how a Aile twirl
fe ae cumient 1s + applied. be the

Aedrode.

4. This AC. will have both tye x -ve phase
When ave phase exists, ¡Lil make Ihe
electrode Ave.

Thus fons ge vepelled

D put when negative phase extets. ih will

make the eledrode —ve
Thus the loge par
But when ve phase again
and make thes wry out of the filles
But. the small patie. sinie they have
gmall mass. they will be ath aded quickly
{han loge particles Bul when +ve phase
exists, they qu repelled E By dhe ime thay
En repelled ue ve phase exfsts a they
eb attracted x they finally crash on
echte THE me
¿Mence lange particle veach the
dekedor 1%. This is called as high pass

Kelten:

>

holes ‘will get altracted
exists They repel

Now let us conside “the ave dedred
1 rode
A DC- cument sf ves fs applied to the

electrode -
Talkiog aqua, the ave charged pasfides

into constderation, We see that va

5. has ee nome ine eisen A ray 008
This is nol a Hille.
An AC. current fs applied to the elechude
The lage patides will qt athacted towards

_ve eledrode -

By Me time it qs dllhacted. the eledsode

become +ve -

Since the large poakidles have quote

mass. they wflt have lo give greater qpace

to ge vepelled away om the elechode -
hy lie time it fs geting vepelled, the

dechode will hum inte Fve

will

me a Ihe

are attracted a they cash :
emall size particles will never”

tre -eledrode > They

lange pnes
But the
e aithacked towards
X out of he Aller

jut q
Thus the small fons alone will make
thea vony cut of the Alte
his is called low pass Hiller
> Since the 'quaduwpale has both changed

dledysdes Whey ad as law ot high pass
Alte jee. double mass Alter
Advantages :

compact and reliable

“low cost analytical toot

6. Detamine the md-wb- in many Lomprung,
To identity the shuchre of many comp,
“Disadvantages :
Ft is a (mo resolution mass analyze
Only one miz rato value can be
obtained at a time.
Broader ‘mlz vats ‘values can be
obtained only offer ony scanning periods.
Not suited 4or pulse fonisalion melfied
Applications :
ne analysis vf gases and
volatile | Mquido.
_ Mainly used tr residual gos analysts
| Used in Le-MS x GC-Ms
Used in both qualitative x quantitative
analysis: | eee
his type of spechomeby ts useful
vohen studyiag. particular fens of interest
sine TE fs able to stay Lned se

ee mn ed que ae

7. Tine 4 fight Mose Analyzer
or analyzers seperate ions by Eme
pofthout the use of an elechic va magnetic field
Jp a aude sense, TOF is similar te
chaomal ahy . except There is no sp Im-p,
iostead the sepaalion is based on the Kinetic

en x. Velocihy of the ions.

Tons are ateeleated by on eledhic field of
Known chrength. Thi acceleration “results fr an
foo having the same kinelic ‘energy 0s any
thier ton. that has the same change The >,
velocity of the fon depends on The mass to chasge
soli Cheavier fons nf the same charge each
Lower speeds):

the Hime that
fon do reach .a dedecor

to meocured

This Hime will depend on the vebay of the
a measure of ats costes. ES
From this vaio and Known

TE subsequently takes for the

ak à Known distance:

fon, and :. fs
charge vaio

expexirnent al parameters; one con identity the ior
source É ANALYZER DETECTOR,
Gg voeuurey)
wool” \ ve tows \
ange \ Fight bike =
KR RR \
site etd L
hele go : =
idl Ge es
DAA po

es valds

Ador Slds Exo: Field free region

8. Peotedure :
A Tor Ms use the differences fo honsit

time ef a diff region to sepasofe ions
of different masses.
Tt operates in a pi
be produced or extracted |
An — electric field accelerotes all fons inf a
ed quee gt region with a kineke ung
que where 9 fe the Ten charge a Vis the oppliel

vatage .
Since the fon kE-is 0.5 mv pie Töns
than heavier fons a

dof the dvift

ulsed mode so ions mut

to pales

have a higher velocity
«each the detedor al the en
seien Soone :

| Tons ove Anmed by pulse * tonization
melhsd. “The fans transverse an evacuated
tube Called “the drift tube to veach the

deledor-* j
“The: tons, leaving the ion source of a Tor Ms

have nélhes exactly the come starting time
nor exacily the dome KE
The velledwoo fs a sexes of rings m
qide thal oct as an fm mir. ES
This refieren compensates pr Ihe spread
to KE. of the fons as they enter the drift
region a Tmproves the vesolukien of Insbument

9. Mpa. DER Sy TE, lo a Ts disploufecl
on an oscilloscope as a undion of Hime bY!
produce the mas spechum-

‚Advantage ;
speed

ay lo reurd en Apehum al
one ime
poor resolu hon
FT-ICR
Power frorefeun Ton eyclelvon , resonance -

Us a magnets Aield orde do hap fons
te "an öl inside dit

Ta tha analyzer there Ts. no een that
pteurs: volhex all he fons of à, par feular rame
ove trapp ed inside, and an applied teal
m a ield helps. do enexdle a signal
E a 54 a

A = 3 E oe
Flees, TE =
# spectrum Achat
—
ay Ra Stabe ue werk

one Jrequenu «y CRF) exces

10. pner Ms fs a Type of más analyze
tov determining The mass de chax vo Ho (mis)
fons of the cyclotron frequency of the Tons fi
oe roque ied vd ie

The fons me happed fo a penning Wap

Ca magnetic field with. elechte hapying. plates
where they ave excited Cal theit svesonant
cycletion droquencie) E a larger eydolren vadius
by an oscillating elechic field ovthogonal to
the Magnete da. + 2

Adler the excitation -field is semoved the
Tons are votating al ‘Thea aydobon frequency
in phase Cas o ‘packet’ of fons).

' “these fons induce a change (detected
as an fmaye current) on a pair of electrodes
as the packets bf fon pass close Lo them .

The resulting signal ts ‘called'a. 4ree
{ndudion decay CFD), “transient ov interjeropam
That consisls of a superposition of ‚sine wave:

The useful signal is extracted 4rom this
data by performing à fourier Aransfem ts
give a mass spechum .

To the simplest dorm the relakonshi
phon: the qydlohon frequency x the oa
lo choage «aho is given by

B

a
f = m

11. where

fe cycloken frequency

4 = ion chupe
B = magoele field sent
m = ón. mas.

This analyze. ernploys etoiles principles as
Me quedrupole analyze, sho uses an electric.
sud 4m ne sepandhon ef Me fons by moss
to charge scatios -

The analyze fo made with a ving
dechode of a specific voltage and guunded
end cap eledrodes

AC oe Dc pas * RF potential is
appli el tehueen the cups, * \he ving eledrode -

The fons enter [he area bhon tre

cledvodes tm one of the end caps.
“There ‘the fons entering nt the chamba

ave topped by eledhomagnelie fields and

\lates in concentric trajectories This
called vesonant ejection. ;
age increases; heavier

they psct
ocess is

As the RF voll
orbits become more stabilized >

mass ‘on
become: les”

and the Might mas tons
stabilized . causing teem fp collide coil

12. the wall, and eltrninating Ihe pao
haveling to and being deleted by He
detector .

Jon sounte ¡ona
sd 8 Sete

ade Y = te

y z
TE da) di

Res ononte AC

RS =
RE = EU
D der

Advantage.

TI ofa quod man ré psc
Types: j
> 3D too hap

— aD ton bap,

BD ion traps :
“They were made up wa cäcular

electrode, with hoo elli rr) cops on. the hop

and the bottom that ‘creates a

; 3D
quadrupslar . yield.

13. “These, Taps Wer
fon Fraps a EA ré
Concephually, a Paul fon bap can be
imagine’ as a quadruple bent in on theelf
jnorder’ lo” form a closed loop, The inne
qod is «educed to. a point at the cemhe of”
the tap. the cuter ved fs the circular ‘eledhede,
gna the: bop, * bottom wods make Up the caps

The overlapping of a dived potential

with an alternative one gives à kind of
“39 quadruple" in which ions of all masses
acre trapped on a 3D tajecuy- BY applying
a resonant 4requenty along z, Me fons

different masses present > together side
the haps are expelled according fo thea

ao as to .obtain the spectrum
As the fons vepel each other in the
trap: Yheia Yrajectories expand as © function of

the time
e Brin cagao tony seat by les, expansion cat
has to be taken te seduted the. rajeduy -

mis 1 accomplished by maïntainig , to the
pressure oh heltum ; qos ushich ‘removes

masses

hop a

accus energy: dem the) ions, by céllision.
This‘ presure hovers and
This foshument Ts vay: simple 2 ,

relativdy Inexpensive.

14. —AD ion trap :

Ar ts: also known as the ee)

analyser based on The 4-70
quadwupole ending fn lenses Anat vepel he Tens
Inside the vods, and thus at tve “potentials
Arrive fons 4 vice versa.

In these haps, fons are confined to “the
vadial dimension by means of à quadrupolar
field and in Ahe axtal dimension by means
of an elediic Ajeld cal the ends of the
tops.

Once in the LIT, the fons ave cooled by
Collision with an inet gas x ly alorg
the z axis behueen Ihe nd electrodes.
while sirnultanesusly oscillating fo Une xy plore
a to the application of an RF only
potential on the mods oy

“The mods are Auxihermore often
divided fnto ‘3 segments, .

Application ef an addikonal De voltage
to the end pom si The quadruprfe also
allows the ' tons te "be happed “This can
be used either without send : elechrodes or
together with thee elechodes.

dad), fs an

15. “These voltages vepel Ihe fons fnside
the líneas trap, and thé repulsion fs high
when the Tons are closer to the nds .

Tons ave thus repelled towards the cenke

the quadruple 14 ot the centre same
repelling voltages ave applied al each end.

Thus. The ion cloud will be squeered
ai the cenbe of quadrupde. iq he applied
voltages are apomekically applied, but can
be located at closer te one end if Ihe
~epelling voltage at that end is smaller -

Tons tapped within
mass ‚elechvelg gjected either along the axis
of the trop Cowial rejechor) o perpendicular
te its. artis Cradial ejector). .

rn commercial Lira 2 modes or le
may seechve ejection’ of” ions ave used: eitha
fe ions ave expelled ondally using bringe.
Held effect by applyiny Ac voltages bhon Me
mods of the Linen trap A the exit lens or
ob are bhollowed out’ in 2 opposite veda
and mas selechve radial expulsion of
ions ts obtained by applying an
appropriate ac “village on These 2 wds

an LIT can be

16. Orbitap

“the orbitiap la on elechioslate fon trap
Yhat uses the Fourier fransform do obtain
mass pedra.

The eternal port is 00 deckede. having he
shape of a bovrel eut foto 2 equal park
with a small talerval. "The central elechede
ts m spindle shape :

The fons axe fnjded tangenttaly

Trough the interstice bhon the 2 parts

of the external eledrode -
An the 8 Commercial fosteument +

Antecion occurs off -ontis Abb a hele in
Ihe exlemal electrode: .

An eleckostakic witage | several
lovd" eve gos rive Tens ‚is applied te the
cenbal electrode, while the cule electrode ts
at ground potential . :

The fons are tojeded, with a
kinehe energy sj teme kiloel ecbron voit à

Kart to oscillale ¿fo Ihe trap fo fnbricale
spirals ground the cenkal elechode unda
the fngluente 64. an elechestatie fel d
with quad learithmic — pofemhial. dishibube
that is blond by Ihe me vel!
ang astute geomehy of the drap. y

17. NN WS
Nene fons ave produced x docused from

Ae by a classical atmesphaie presure
Goce Coupliggdedaar analytical quadvapele, &
sprafe linear deep a re crap it

The fon trap G has he particularity lo
all Tt fe accumulate be fons dose to Ihe
exit te the exbitrap , adjustigy Ihe potential:
on he F electrode x on “the last segment G of
jhe Hop: "This, allmos asta ‘injection toto the
Ailes -

Switching "Ihe applied veltoges “pow those
prognted gqpaphically in the lower’ left pana
A the Ajgure to those fo “the right panel allox
injedion fo a. vay short Eme falo the erbitrap
at sore Kilo elechen volts :

From nt au he ‘ions 4y Areely except
cr a deflection of the beam’ te aveid
injection of He am Me linear tap in evil

This Field- free li 1 dlislance is
adjusted to take account | a well Know
property of the TOF fashument in which line
fs a cus plane at twice lla length 4
the acceleration vaio y where fons of
the game mas ave Ap cused an.ceesively.

The distance nl T fs adjusted te

correspond to thi focusing distance.

18. This allows the injection ol fons of bue
mlz at a time, dptused fo o chord ne
period of some ns, fora tal injection me
oh obout Ips 4m macoenively high volz ions.

This leads Aube ko an efficient rupg
of Fons. ch the same mas, Tmpreving then
detector ushile dispersig ls $ different
pues veduce the space choage geh

As the Hime needed do Injech ions coil
Ja same mlz is much, Sherles Than The
Free of ‘me. oscillation alomz, fe movement
| Yet “ions wilh be. very coherent, Adi
tie: défelion. y reas

The rotation arround the central electrode
does not have thi coherence, reducing the
background noise. Furthermore, this good
Cohen ance | {improves the mas veastuken a
acuer: 150000 FWHM resolu on
RUE ap ete

Io)

no Blechosprey source.

B— lens Srranemert te oblain. 2 - spr

Co Ri quadruele w ion guido

19. pales

g> hengal RE aquadrupde

G > Samented repping guadngcle lo store Me
rl to ‘yet | !

gan lenes

T— device te deflect Ihe im beam prier À
injechen in the ovethap

k > orkihap sele view

3 > vepella elechode.