More about chromatography

Rtx-1614

(Optimalized 5% phenyl methyl phase)

• Higher sensitivity and inertness for BDE-209 mean more accurate, reproducible results.
• Meets all EPA Draft Method 1614 requirements for resolution, tailing factors, and retention.
• Unique deactivation, ideal for routine screening of polybrominated diphenyl ethers.

Application

• Polybrominated diphenyl ethers

RT®-S-BOND Plot Column

(divinyl benzene 4-vinylpyridine)

• Not moisture sensitive.
• Intermediate polarity phase.
• Use for the analysis of nonpolar and polar compounds.

Restek chemists have developed a new process for the manufacturing of porous polymer PLOT columns. The process incorporates the particles to the walls of the tubing, so there is virtually no particle generation. Because of the particle adhering to the walls of the tubing, there is reproducible performance from column to column, including selectivity and flow.

Application

• Analysis of solvent mixture

Rt-Alumina BOND PLOT Columns (deactivated by Na2SO4)

(Aluminium oxid deactivated by Na₂SO₄)

• Highly selective adsorbent for C1-C5 hydrocarbons; separates all unsaturated hydrocarbon isomers at temperatures far above ambient.
• Reactivity of aluminum oxide stationary phase is minimized so that column response for polar unsaturates, such as dienes, is optimized. Column sensitivity or response ensures a linear and quantitative chromatographic analysis for these compounds.
• Strong bonding prevents particle generation. The column can be used in valve switching operations, without release of particles that can harm the injection and detection systems.
• The Rt™-Alumina PLOT column is stable up to 200°C. If water is adsorbed on the column, it can be regenerated by conditioning at 200°C. Full efficiency and selectivity will be restored.

Selectivity

The selectivity of the Rt™-Alumina PLOT column is measured by the retention indices for acetylene and propadiene. These two components are extremely sensitive for a change in selectivity.

For saturates, retention is determined mainly by the volatility of the compound, with less volatile compounds retained longer than more volatile compounds. For example, isoparaffins are less retained than less volatile normal paraffins of similar carbon number.

For unsaturates, retention is strongly influenced by polarity or degree of unsaturation. In general, hydrocarbons having a higher degree of unsaturation are more polar. This polarity comes from the presence of π electrons; the more π electrons present in a compound, the more polar it behaves and the more strongly it is retained.

Sensitivity

Proper deactivation is critical to minimize reactivity of the aluminum oxide stationary phase and maximize column sensitivity. Quantitation can be done only if the column exhibits linear response, which results from good stationary phase inertness. Rt™-Alumina PLOT columns are specially deactivated and provide high inertness for unsaturates and saturates. In fact, Rt™-Alumina PLOT columns are almost four times more sensitive for unsaturates than other brands on the market.

Guaranteed Reproducibility

Each Rt™-Alumina PLOT column is tested with a hydrocarbon test mix to ensure proper phase thickness and deactivation (see figure). Pentane is used to calculate k (capacity factor), which is a measure of phase thickness. The ratio of isobutane to acetylene retention is measured to ensure proper deactivation of the alumina oxide layer. The plates per meter value is calculated to evaluate column efficiency.

Restek’s Rt™-Alumina PLOT columns offer fast and reproducible hydrocarbon stream and purity analyses. The 0.32mm ID Rt™-Alumina PLOT column provides fast and efficient analysis of C1 to C5 hydrocarbons. The higher capacity of the 0.53mm ID Rt™-Alumina PLOT column makes it ideal for purity analysis of many common petrochemicals, such as 1,3-butadiene, ethylene, and propylene.

Application

• C1 - C5 hydrocarbons
• Purity analysis of ethylene, propylene, butenes, butadiene

Rt®-Q-BOND PLOT Column

(100% divinylbenzene)

• Not moisture sensitive.
• Non polar phase.
• Excellent for analysis of C1 to C3 isomers and alkanes up to C12.
• CO₂ and methane separated from O₂/N₂/CO (Note: O₂/N₂/CO not separated at room temperature).
• Use for analysis of oxygenated compounds and solvents.

Restek chemists have developed a new process for the manufacturing of porous polymer PLOT columns. The process incorporates the particles to the walls of the tubing, so there is virtually no particle generation. Because of the particle adhering to the walls of the tubing, there is reproducible performance from column to column, including selectivity and flow.

Application

• Subambiente analysis of Permanent gases
• Hydrocarbon gases
• Solvents

Rt®-QS-BOND PLOT Column

(porous divinyl benzene homopolymer)

• Not moisture sensitive.
• Intermediate polarity PLOT column.
• Separates ethane, ethylene and acetylene to baseline.

Restek chemists have developed a new process for the manufacturing of porous polymer PLOT columns. The process incorporates the particles to the walls of the tubing, so there is virtually no particle generation. Because of the particle adhering to the walls of the tubing, there is reproducible performance from column to column, including selectivity and flow.

Application

• Hydrocarbons gases.
• Fully resolves ethylene, acetylene, and ethane.
• Subambiente analysis of Permanent gases

Rt-Msieve 5A Plot Columns

(Molecular sieve 5A)

Rt™-Msieve 5A PLOT columns are designed for efficient separation of Ar/O₂ and other permanent gases, including CH₅, C₂H₆, and CO. Special coating and deactivation procedures ensure chromatographic efficiency and the integrity of the porous layer coating. The high surface area of the Rt™-Msieve is generated by the pore structure present in the molecular sieve. Only compounds that can enter the pores will be exposed to this surface and will be retained. Molecular sieves have very high retention, allowing separations of permanent gases at temperatures above ambient. Additionally, Restek’s unique immobilization process guarantees that the uniform particles remain adhered to the tubing - even after continuous valve-cycling.

The deactivation technology also allows the CO peak to elute as a sharp peak. This is in contrast with other suppliers where CO often tails badly and cannot be quantified below % levels.

Application

• Permanent gas analysis
• Separation of Ar/O2 and H2/He at ambient temperature or above
• He, Ne, Ar, O₂, Xe, Rn, SF₆, CH₄, C₂H₆, CO
• Refinery or natural gas

Rt®-U-BOND PLOT Column

(divinylbenzene ethylene glycol/dimethylacrylate)

• Not moisture sensitive.
• Highly polarity phase.
• Use for the analysis of polar and nonpolar compounds.

Restek chemists have developed a new process for the manufacturing of porous polymer PLOT columns. The process incorporates the particles to the walls of the tubing, so there is virtually no particle generation. Because of the particle adhering to the walls of the tubing, there is reproducible performance from column to column, including selectivity and flow.

Application

• Unsataruted compounds
• Hydrocarbon gases
• Polar solvents

Rt-TCEP

(1,2,3-tris[2-kyanoetoxy]propan)

• Ideal for aromatics and oxygenates in gasoline.

Most gasolines contain aliphatic hydrocarbons up to n-dodecane (C12). To improve identification of the aromatics and oxygenates, it is desirable to elute benzene after C11 and toluene after C12. The extremely polar Rt™-TCEP stationary phase provides a retention index for benzene greater than 1100 and permits the separation of alcohols and aromatics from the aliphatic constituents in gasoline.

Rt™-TCEP columns have the same high polarity as TCEP packed columns (precolumns in ASTM Method D4815 for the analysis of petroleum oxygenates), with the efficiency of a capillary column. The result is a column that can separate a wide variety of compounds with an elution pattern unattainable using other high polarity siloxanes.

The Rt™-TCEP column incorporates a nonbonded stationary phase coated on a surface specialized for enhanced polymer stability and extended column lifetime. Solvent rinsing should be avoided. Conditioning is necessary only if the column is to be used at temperatures near the maximum operating temperature.

Applications

• Aromatics and oxygenates in gasoline

Rtx-OPPesticides2

• Application-specific columns for organophosphorus pesticides; best column combination for US EPA Method 8141A.
• Low bleed--ideal for GC/FPD, GC/NPD, or GC/MS analyses.

Using sophisticated computer modeling software, we created two stationary phases for separating the 55 organophosphorus pesticides (OPP) listed in EPA Method 8141A. Separation is improved, and analysis time is significantly reduced, compared to other columns. The extended upper temperature limit of these phases (330°C) allows analysts to bake out high molecular weight contamination typically associated with pesticide samples. The low bleed columns are a perfect match for sensitive detection systems.

Applications

• Organophosphorus pesticides

Rtx-OPPesticides

• Application-specific columns for organophosphorus pesticides; best column combination for US EPA Method 8141A.
• Low bleed--ideal for GC/FPD, GC/NPD, or GC/MS analyses.

Using sophisticated computer modeling software, we created two stationary phases for separating the 55 organophosphorus pesticides (OPP) listed in EPA Method 8141A. Separation is improved, and analysis time is significantly reduced, compared to other columns. The extended upper temperature limit of these phases (330°C) allows analysts to bake out high molecular weight contamination typically associated with pesticide samples. The low bleed columns are a perfect match for sensitive detection systems.

Applications

• Organophosphorus pesticides