gc columns

GC COLUMNS | CAPILLARY COLUMNS
Selecting a GC Column
Structures, polarities, properties, and uses for Restek capillary column phases, in order of increasing polarity
Rxi®-1ms, Rxi®-1HT,
Rtx®-1
100% dimethyl polysiloxane
Rxi®-5ms, , Rxi®-5HT,
Rtx®-5, Rtx®-5MS
5% diphenyl/95% dimethyl polysiloxane
Rxi®-5Sil MS
5% phenyl
95% dimethyl arylene polysiloxane
Rtx®-20
20% diphenyl
80% dimethyl polysiloxane
CH 3
CH 3
CH 3
CH 3
CH 3
CH 3
Si
O
Si
O
Si
O
Si
O
Si
Si
O
Si
O
Si
O
CH 3
CH 3
CH 3
CH 3
CH 3
CH 3
100%
Polarity: nonpolar
Uses: solvents, petroleum products,
[G1] pharmaceutical samples, waxes
5%
95%
Polarity: slightly polar
Uses: flavors, environmental,
[G27] aromatic hydrocarbons
X
Polarity: slightly polar
Uses: flavors, environmental,
pesticides, PCBs, aromatic
hydrocarbons
y
20%
80%
Polarity: slightly polar
Uses: volatile compounds, alcohols
[G32]
Rtx®-1301, Rtx®-624, Rtx®-G43
6% cyanopropylphenyl
94% dimethyl polysiloxane
Rxi®-624Sil MS
6% cyanopropylphenyl
94% dimethyl arylene polysiloxane
Rtx®-35
35% diphenyl
65% dimethyl polysiloxane
Rxi®-35Sil MS
35% phenyl
65% dimethyl arylene polysiloxane
C N
Si
O
CH 3
Si
O
C N
CH 3
O Si
CH 3
CH 3
O Si
CH 3
CH 3
O Si
CH 3
R
CH 3
X Y Z
Si
CH 3
Si
35%
O
CH 3
Si
CH 3
65%
O
O Si
CH 3
O Si
CH 3
CH 3
O Si
CH 3
R
CH 3
35% X Y
Si
CH 3
(CH 2 ) 3
CH 3
6%
94%
Polarity: slightly polar
Uses: volatile compounds, insecticides, residue
[G43] solvents in pharmaceutical products
Polarity: intermediately polar
Uses: volatile compounds, insecticides, residue
solvents in pharmaceutical products
Polarity: intermediately polar
Uses: pesticides, Aroclor PCBs, amines,
[G42] nitrogen-containing herbicides
Polarity: intermediately polar
Uses: pesticides, Aroclor PCBs, amines,
nitrogen-containing herbicides
Rtx®-200
trifluoropropylmethyl polysiloxane
Rtx®-50
50% phenyl
50% methyl polysiloxane
Rxi®-17
50% diphenyl
50% dimethyl polysiloxane
Rxi®-17Sil MS
50% phenyl
50% dimethyl arylene polysiloxane
CF 3
CH 3
C 2 H 4
Si
CH 3
O
Polarity: selective for lone pair electrons
Uses: environmental, solvents,
[G6]
Freon ® gases, drugs, ketones, alcohols
Si
CH 3
100%
O
Polarity: intermediately polar
Uses: FAMEs, carbohydrates
[G3]
Si
O
Si
CH 3
50%
50%
Polarity: intermediately polar
Uses: triglycerides, phthalate
[G3] esters, steroids, phenols
O
O Si
X
CH 3
O Si
CH 3
y
CH 3
O Si
CH 3
R
Polarity: intermediately polar
Uses: triglycerides, phthalate
esters, steroids, phenols
CH 3
Si
CH 3
z
Rtx®-1701
14% cyanopropylphenyl
86% dimethyl polysiloxane
Rtx®-65, Rtx®-65TG
65% diphenyl
35% dimethyl polysiloxane
Rtx®-225
50% cyanopropylmethyl
50% phenylmethyl polysiloxane
Rt®-2330
90% biscyanopropyl
10% cyanopropylphenyl polysiloxane
C N
CH 3
C N
C N
C N
(CH 2 ) 3
CH 3
Si
O
CH 3
Si
O
Si
O
Si
CH 3
O
Si
O
Si
O
(CH 2 ) 3
Si
O
(CH 2 ) 3
Si
O
(CH 2 ) 3
CH 3
14%
86%
Polarity: intermediately polar
Uses: pesticides, Aroclor PCBs, alcohols,
[G46] oxygenates
65%
Polarity: intermediately polar
Uses: triglycerides, rosin acids,
free fatty acids
35%
CH 3
50%
50%
Polarity: polar
Uses: FAMEs, carbohydrates
[G7]
C N
90%
10%
Polarity: polar
Uses: cis/trans FAMEs, dioxin isomers,
[G48] rosin acids
Stabilwax®, Rtx®-Wax
Carbowax ® PEG
H H
C C O
H H
note
Structures, polarities, and properties also apply
to metal MXT® stationary phases.
Polarity: polar
Uses: FAMEs, flavors, acids, amines,
[G16] solvents, xylene isomers
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