Rtx-200 GC Columns

Excellent retention and separation of intermediate polar compounds

  • Unique polymer composition provides excellent retention and separation of intermediate polar compounds.
  • Higher thermal stability ensures low bleed for sensitive detectors.
  • Stable deactivation provides consistent retention, efficiency, and inertness. 
  • Pro EZGC libraries for simplified method development and optimization.

Unique Polymer Composition Enables Unique Selectivity

Restek’s Rtx-200 GC columns are coated with a trifluoropropylmethylpolysiloxane stationary phase, which provides a unique selectivity for compounds that display lone pair electrons, such as ketones, aldehydes, nitro-containing compounds, and halogen-containing compounds. The distinctive polarity of Rtx-200 columns ensures separations that often cannot be achieved with either nonpolar or polar columns—making them suitable for a broad range of analyses.

Using our Pro EZGC software to model GC separations, the retention of several common solvents was determined for three columns of different polarities: a nonpolar Rtx-1 column, a midpolar Rxi-624Sil MS column, a selective Rtx-200 column (Figure 1). Under identical analytical conditions, Rtx-200 columns provide complete resolution of these solvents and a different elution order compared to either a Rtx-1 or Rxi-624Sil MS column.

Figure 1: The unique polarity of Rtx-200 columns separates common solvents better than a nonpolar Rtx-1 column, or a midpolar Rtx-624Sil MS column.


Rtx-200 column polarity


Rtx-1 column polarity

Rtx-624Sil MS

Rtx-624Sil MS column polarity


  1. Chloromethane
  2. Methanol
  3. Bromomethane
  4. Methylene Chloride
  5. tert-Butyl Alcohol
  6. Chloroform
  7. Benzene
  8. 1,2-Dichloroethane
  9. Dibromomethane
  10. Fluorobenzene
  11. 2-Chloroethanol
  12. Toluene
  13. Tetrachloroethene
  14. Ethylbenzene
  15. Chlorobenzene
  16. o-Xylene
  17. Styrene
  18. n-Propylbenzene
  19. Naphthalene


Column: 30 m, 0.32 mm ID, 1.0 µm
Carrier Gas: Helium, Constant Flow @ 2.0 mL/min
Average Velocity: 40.88 cm/sec
Outlet Pressure (abs): 14.70 psi
Oven Temp.: 35 °C (hold 1 min) to 235 °C @ 30 °C/min

High Thermal Stability and Low Bleed—Ready for MS

The stable column chemistry of Rtx-200 allows thermal stability to 360 °C with low bleed. The high thermal stability of the Rtx-200 phase makes it compatible with sensitive detectors and analyses that require high temperatures.

For applications that require even lower bleed, our Rtx-200MS columns have a bleed specification lower than that of Rtx-200, making them ideal for labs using sensitive mass specs.

Figure 2: The excellent thermal stability of Rtx-200 columns ensures low bleed, even at elevated temperatures.

ColumnRtx-200ms, 30 m, 0.25 mm ID, 0.25 µm (cat.# 15623)
Standard/SampleInstrument blank
Oven Temp.:40 °C to 280 °C at 10 °C/min (hold 10 min) to 300 °C at 20 °C/min (hold 10 min) to 340 °C at 20 °C/min (hold 10 min)
Carrier GasHe, constant flow
Flow Rate:1.4 mL/min
Linear Velocity:32.113 cm/sec @ 40 °C
Dead Time:1.54 min @ 40 °C
DetectorFID @ 300 °C
Make-up Gas Flow Rate:30 mL/min
Hydrogen flow:40 mL/min
Air flow:400 mL/min
Data Rate:50 Hz
InstrumentAgilent 7890B GC


Figure 3: Rtx-200 columns exhibit low bleed at 360 °C, even for high molecular weight compounds like siloxanes that require higher temperatures.

ColumnRtx-200, 15 m, 0.25 mm ID, 0.25 µm (cat.# 15020)
Standard/SamplePolymethyl siloxane
Inj. Vol.:1.0 µL split
Inj. Temp.:250 °C
Oven Temp.:40 °C to 360 °C at 15 °C/min (hold 30 min)
Carrier GasH2, constant flow
Linear Velocity:40 cm/sec
DetectorFID @ 360 °C
NotesFID sensitivity: 5.12 x 10-10 AFS
Split vent: 40 cc/min.


Rtx-200 columns are available in a variety of dimensions (lengths, IDs, and film thicknesses), and can be used for a broad range of applications, from solvents to silanes to pesticides. Due to its neutrality and inertness, Rtx-200 columns can be used to analyze acidic, basic, or neutral compounds. Its unique polarity also makes it an ideal confirmation column for many analyses because it will produce a different elution pattern compared to most other stationary phases.


The Rtx-200 is the best non-PLOT column option that can be used with GC-MS without the need for a particle trap or cryofocusing for chlorofluorcarbons (CFCs).  This stationary phase’s unique selectivity exhibits the best retention and separation of these specific commonly found halogenated compounds (Figure 4).

Figure 4: Rtx-200 columns exhibit excellent retention and separation of chlorofluorocarbons (CFCs).

ColumnRtx-200, 105 m, 0.25 mm ID, 1.00 µm (cat.# 15059)
Standard/SampleDichlorodifluoromethane (cat.# 30275)
Freons standard (custom)
Trichlorofluoromethane (cat.# 30421)
Conc.:500 ppm
Inj. Vol.:1 µL split (split ratio 400:1)
Liner:Topaz 4.0 mm ID Precision inlet liner w/ wool (cat.# 23305)
Inj. Temp.:250 °C
Split Vent Flow Rate:400 mL/min
Gas Saver Time:2 min
Gas Saver Flow Rate:20 mL/min
Oven Temp.:32 °C (hold 20 min)
Carrier GasHe, constant flow
Flow Rate:1 mL/min
Linear Velocity:19.303 cm/sec @ 32 °C
Dead Time:9.553 min @ 40 °C
Scan Program:
GroupStart Time
Scan Range
Scan Rate
Transfer Line Temp.:250 °C
Analyzer Type:Quadrupole
Source Type:Extractor
Source Temp.:230 °C
Quad Temp.:150 °C
Electron Energy:1708 eV
Tune Type:PFTBA
Ionization Mode:EI
InstrumentAgilent 7890B GC & 5977B MSD
Sample PreparationStandards were combined and diluted to 500 ppm, then transferred to a 2 mL vial (cat.# 21142) and capped with a short screw cap (cat.# 24498).



Chlorosilanes are volatile, reactive compounds used as silylating agents and intermediates for silicone synthesis. Due to their highly reactive nature, these compounds are difficult to analyze by GC. However, a 60 m, 0.53 mm ID 3.0 µm Rtx-200 column can successfully analyze a wide range of chlorosilane compounds (Figure 5).

Figure 5: Reactive chlorosilanes analyzed using a 60 m Rtx-200 column.

ColumnRtx-200, 60 m, 0.53 mm ID, 3.00 µm (cat.# 15088)
Standard/SampleMethyl silanes
Inj. Vol.:0.5 µL split
Inj. Temp.:200 °C
Oven Temp.:40 °C to 250 °C at 8 °C/min (hold 5 min)
Carrier GasH2, constant flow
Linear Velocity:40 cm/sec
DetectorFID @ 270 °C
NotesFID sensitivity: 1.02 x 10-9 AFS
Split vent: 40 cc/min.



Testing solvent purity or analyzing solvents from manufacturing processes requires a column that quickly and accurately resolves a variety of industrial solvents. Rtx-200 columns are ideal for analyzing a wide range of common industrial solvents (Figure 6).

Figure 6: Rtx-200 columns can quickly and accurately analyze a wide variety of common solvents.

ColumnRtx-200, 60 m, 0.53 mm ID, 3.00 µm (cat.# 15088)
Standard/SampleSolvent mix #2
Inj. Vol.:1.0 µL split
Inj. Temp.:275 °C
Split Vent Flow Rate:50 mL/min.
Oven Temp.:40 °C (hold 5 min) to 285 °C at 5 °C/min
Carrier GasHe, constant flow
Linear Velocity:40 cm/sec
Source Temp.:285 °C
NotesTIC using open split interface (OSI).


Pesticides in Dietary Supplements GCxGC (Secondary Column)

As shown by the extensive spread along the x and y axes, a GCxGC analysis with Rxi-5Sil and Rtx-200 columns easily separates and quantifies compounds with isobaric interferences, such as 2,4'-DDT and 4,4'-DDD (Figure 7).

Figure 7: Excellent two-dimensional separation of pesticides using orthogonal column set of Rxi-5Sil MS and Rtx-200 columns. Note 2D separation of compounds that have isobaric interferences when coeluting on Rxi-5Sil MS, 2,4’-DDT and 4,4’-DDD.

ColumnRxi-5Sil MS 30 m, 0.25 mm ID, 0.25 µm (cat.# 13623)
Rtx-200 1.5 m, 0.18 mm ID, 0.20 µm (cat.# 45001)
Standard/SampleMixed pesticide standard
Conc.:2 ng/µL
Inj. Vol.:1 µL splitless (hold 1 min)
Liner:Gooseneck Splitless (4mm) w/Wool
Inj. Temp.:250 °C
Purge Flow:40 mL/min
Oven Temp.:Rxi-5Sil MS: 80 °C (hold 1 min) to 310 °C at 4 °C/min (hold 1.5 min)
Rtx-200: 90 °C (hold 1 min) to 320 °C at 4 °C/min (hold 1.5 min)
Carrier GasHe, constant flow
Flow Rate:1.8 mL/min
Modulator Temp. Offset:25 °C
Second Dimension Separation Time:4 sec
Hot Pulse Time:1.2 sec
Cool Time between Stages:0.8 sec
Transfer Line Temp.:290 °C
Analyzer Type:TOF
Source Temp.:225 °C
Electron Energy:70 eV
Mass Defect:-20 mu/100 u
Solvent Delay Time:4 min
Ionization Mode:EI
Acquisition Range:45 to 550 amu
Spectral Acquisition Rate:100 spectra/sec
InstrumentLECO Pegasus 4D GCxGC-TOFMS
NotesLiner cat.# 22405 was used to produce this chromatogram, but has since been discontinued. For assistance choosing a replacement for this application, contact Restek Technical Service or your local Restek representative.
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See application note GNAN1338 for extraction and cleanup details. A 1.5 m length of the Rtx-200 column was trimmed from a 10 m column. Columns were connected with a Universal Press-Tight Connector (cat.# 20429). See chromatogram GC_FF1187 for full scale view.

Simplified Analysis Optimization with Pro EZGC Software

Rtx-200 columns are supported by our Pro EZGC chromatogram modeler, allowing labs to simplify their analysis optimization. This free, easy-to-use software helps you perform GC method optimization and method development in minutes—without needing to use an instrument.

Figure 8: Rtx-200 GC columns are supported by Restek’s Pro EZGC chromatogram modeler, helping labs quickly and easily optimize their analysis.

Rtx-200 GC columns are supported by Restek’s Pro EZGC chromatogram modeler