GC COLUMNS Selecting a GC Column - Restek

1 GC COLUMNS . Selecting a GC Column Structures, Polarities, Properties, and Uses for Restek capillary Column Phases, in Order of Increasing Polarity Rxi -1ms, Rxi -5ms, Rxi -5HT, Rxi -5 Sil MS Rtx -20. Rxi -1HT, Rtx -1 Rtx -5, Rtx -5MS 1,4-bis(dimethylsiloxy)phenylene Diphenyl dimethyl polysiloxane Dimethyl polysiloxane Diphenyl dimethyl polysiloxane dimethyl polysiloxane CH3 CH3 CH3 CH3 CH3 CH3. Si O Si O Si O Si Si O Si O Si O Si O. CH3 CH3 CH3 CH3 CH3 CH3. 100% 5% 95% 5% 95% 20% 80%. Similar to: (100%-methyl)-polysiloxane Similar to: (5%-phenyl)-methylpolysiloxane Similar to: (5%-phenyl)-methylpolysiloxane Similar to: (20%-phenyl)-methylpolysiloxane Polarity: nonpolar Polarity: slightly polar Polarity: slightly polar Polarity: slightly polar Uses: solvents, petroleum products, Uses: flavors, environmental, Uses: flavors, environmental, pesticides, Uses.

2 Volatile compounds, alcohols [G1] pharmaceutical samples, waxes [G27] aromatic hydrocarbons PCBs, aromatic hydrocarbons [G28] [G32]. [G2] [G38] [G36]. Rtx -1301, Rtx -624, Rtx -G43 Rxi -624 Sil MS Rtx -35 Rxi -35 Sil MS. Cyanopropylmethyl phenylmethyl polysiloxane Diphenyl dimethyl polysiloxane C N C N. (CH2)3 CH3 CH3 CH3 CH3 CH3 CH3 CH3. (CH2)3 CH3. Si O Si R Si O Si O Si O Si O Si O Si R Si O Si O. Si O Si O Si O. CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3. x y z x y 94% 35% 65% x y 65%. Similar to: (6%-cyanopropylphenyl)- Similar to: (6%-cyanopropylphenyl)- Similar to: (35%-phenyl)-methylpolysiloxane Similar to: (35%-phenyl)-methylpolysiloxane methylpolysiloxane methylpolysiloxane Polarity: intermediately polar Polarity: intermediately polar Polarity: intermediately polar Polarity: intermediately polar Uses: pesticides, PCBs, amines, Uses: pesticides, PCBs, amines, Uses: volatile compounds, insecticides Uses.

3 Volatile compounds, insecticides, residue [G42] nitrogen-containing herbicides nitrogen-containing herbicides [G43] solvents in pharmaceutical products Rtx -200 Rtx -50 Rxi -17 Rxi -17 Sil MS. Trifluoropropylmethyl polysiloxane Phenyl methyl polysiloxane Diphenyl dimethyl polysiloxane CF3 CH3 CH3 CH3 CH3. (CH2)2 Si O Si R Si O Si O. Si O Si O. Si O. Si O CH3 CH3 CH3 CH3. CH3. 50% 50% x y 50%. CH3 100%. Similar to: (trifluoropropyl)-methylpolysiloxane Similar to: (50%-phenyl)-methylpolysiloxane Similar to: (50%-phenyl)-methylpolysiloxane Similar to: (50%-phenyl)-methylpolysiloxane Polarity: selective for lone pair electrons Polarity: intermediately polar Polarity: intermediately polar Polarity: intermediately polar Uses: environmental, solvents, Freon gases, Uses: FAMEs, carbohydrates Uses: triglycerides, phthalate Uses: triglycerides, phthalate [G6] drugs, ketones, alcohols [G3] [G3].

4 Esters, steroids, phenols [G3]. esters, steroids, phenols Rtx -1701 Rtx -65, Rtx -65TG Rtx -225 Rtx -2330. Cyanopropylmethyl phenylmethyl polysiloxane Diphenyl dimethyl polysiloxane Cyanopropylmethyl phenylmethyl Biscyanopropyl cyanopropylphenyl polysiloxane C N polysiloxane C N. (CH2)3 CH3 CH3. C N (CH2)3 C N. Si O Si O Si O Si O Si O. (CH2)3 Si O (CH2)3. CH3 CH3 CH3 CH3. Si O Si O Si O. (CH2)3. x y z 65% 35%. CH3 CH3. Similar to: (14%-cyanopropylphenyl)-methylpolysiloxa ne Similar to: (65%-phenyl)-methylpolysiloxane C N.

5 Polarity: intermediately polar Polarity: intermediately polar 50% 50% 90% 10%. Uses: pesticides, PCBs, alcohols, oxygenates Uses: triglycerides, rosin acids, free fatty acids [G46] [G17] Similar to: (50%-cyanopropylmethyl)- Similar to: (95%-cyanopropyl)-phenyl polysiloxane methylphenylpolysiloxane Polarity: polar Polarity: polar Uses: cis/trans FAMEs, dioxin isomers, rosin acids Uses: FAMEs, carbohydrates [G8] [G48]. [G7] [G19]. Stabilwax , Rtx -Wax, Stabilwax -MS. Polyethylene glycol H H note C C O Structures, polarities, and properties also apply to metal MXT stationary phases.

6 H H. Polarity: polar Uses: FAMEs, flavors, acids, amines, solvents, xylene isomers [G14] [G15] [G16] [G20] [G39]. 15.