27
GCCOLUMNS |
CAPILLARYCOLUMNS
Selecting a GC Column
Si
CH
3
CH
3
CH
3
CH
3
Si
O
O
CH
3
CH
3
Si
X
y
Structures,polarities,properties, anduses forRestekcapillarycolumnphases, inorderof increasingpolarity
Polarity: nonpolar
Uses:
solvents, petroleum products,
pharmaceutical samples, waxes
Polarity: slightly polar
Uses:
flavors, environmental,
aromatic hydrocarbons
Polarity: slightly polar
Uses:
volatile compounds, insecticides, residue
solvents in pharmaceutical products
CH
3
CH
3
Si
100%
O
CH
3
CH
3
Si
95%
O
Si
5%
O
CH
3
(CH
2
)
3
CH
3
Si
94%
O
Si
C N
6%
O
CH
3
CH
3
Si
80%
O
Si
20%
O
CH
3
CH
3
Si
50%
O
Si
50%
O
CH
3
CH
3
Si
65%
O
Si
35%
O
CH
3
(CH
2
)
3
CH
3
Si
86%
O
Si
C N
14%
O
Rtx
®
-1701
14% cyanopropylphenyl
86% dimethyl polysiloxane
Rtx
®
-35
35% diphenyl
65% dimethyl polysiloxane
Rtx
®
-20
20% diphenyl
80% dimethyl polysiloxane
Rxi®-1ms, Rxi®-1HT,
Rtx
®
-1
100% dimethyl polysiloxane
Rxi®-5ms, , Rxi®-5HT,
Rtx
®
-5, Rtx®-5MS
5% diphenyl/95% dimethyl polysiloxane
Rtx
®
-1301,Rtx®-624,Rtx®-G43
6% cyanopropylphenyl
94% dimethyl polysiloxane
Polarity: slightly polar
Uses:
volatile compounds, alcohols
Polarity: intermediately polar
Uses:
pesticides, AroclorPCBs, amines,
nitrogen-containing herbicides
Polarity: intermediately polar
Uses:
pesticides, AroclorPCBs, alcohols,
oxygenates
[G1]
[G27]
[G43]
[G32]
[G42]
[G46]
note
Structures, polarities, andpropertiesalsoapply
tometalMXT® stationaryphases.
Polarity: selective for lone pair electrons
Uses:
environmental, solvents,
Freon
®
gases, drugs, ketones, alcohols
Polarity: intermediately polar
Uses:
triglycerides, rosin acids,
free fatty acids
Polarity: intermediately polar
Uses:
triglycerides, phthalate
esters, steroids, phenols
CH
3
CH
3
Si
35%
O
Si
65%
O
CH
3
CF
3
C
2
H
4
Si
O
Rxi
®
-17
50% diphenyl
50% dimethyl polysiloxane
y
X
z
Si
O
R
CH
3
CH
3
Si
O
O
CH
3
CH
3
Si
CH
3
CH
3
Si
Rxi
®
-17SilMS
50% phenyl
50% dimethyl arylene polysiloxane
35%
X
Y
Si
O
R
CH
3
CH
3
Si
O
O
CH
3
CH
3
Si
CH
3
CH
3
Si
Rxi
®
-35SilMS
35% phenyl
65% dimethyl arylene polysiloxane
Rtx®-65, Rtx
®
-65TG
65% diphenyl
35% dimethyl polysiloxane
Rtx
®
-200
trifluoropropylmethyl polysiloxane
[G3]
[G6]
Polarity: polar
Uses:
FAMEs, carbohydrates
Polarity: polar
Uses:
FAMEs, flavors, acids, amines,
solvents, xylene isomers
Polarity: polar
Uses:
cis/trans FAMEs, dioxin isomers,
rosin acids
CH
3
(CH
2
)
3
CH
3
Si
50%
O
Si
C N
50%
O
H
H
C C O
H
H
(CH
2
)
3
Si
C N
90%
O
C N
(CH
2
)
3
Si
C N
10%
O
Rtx
®
-225
50% cyanopropylmethyl
50% phenylmethyl polysiloxane
Stabilwax®, Rtx®-Wax
Carbowax
®
PEG
Rt®-2330
90% biscyanopropyl
10% cyanopropylphenyl polysiloxane
[G7]
Polarity: intermediately polar
Uses:
FAMEs, carbohydrates
CH
3
Si
100%
O
Rtx®-50
50% phenyl
50%methyl polysiloxane
[G3]
Polarity: slightly polar
Uses:
flavors, environmental,
pesticides, PCBs, aromatic
hydrocarbons
Rxi®-5SilMS
5% phenyl
95% dimethyl arylene polysiloxane
[G16]
[G48]
Rxi®-624SilMS
6% cyanopropylphenyl
94% dimethyl arylene polysiloxane
X
Y
Z
Si
O
R
CH
3
CH
3
CH
3
C N
CH
3
Si
O
O
CH
3
CH
3
Si
CH
3
CH
3
Si
Polarity: intermediately polar
Uses:
volatile compounds, insecticides, residue
solvents in pharmaceutical products
Polarity: intermediately polar
Uses:
pesticides, AroclorPCBs, amines,
nitrogen-containing herbicides
Polarity: intermediately polar
Uses:
triglycerides, phthalate
esters, steroids, phenols
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TelNo : 03 9762 2034 . . . inAUSTRALIA
Mar 2011
