Restek has optimized molecular sieve 5A and 13X columns for trace analyses, including difficult analytes like oxygen and carbon monoxide. Example chromatograms show sharp, symmetric peaks for permanent gases.
The results of a simulated distillation analysis are vitally important to the operation of refineries globally. For the analysis of petroleum samples within the boiling point range from 55.5 ˚C to 538 ˚C, ASTM D2887 is a standard method that has been accepted and is used industry-wide. This application note will demonstrate how a creative use of the Restek GC Accelerator oven insert kit can permit analysts using Agilent 6890/7890 GCs with 100/120 V ovens to successfully migrate from D2887’s slower Procedure A conditions to the accelerated Procedure B conditions without new instrumentation or software, resulting in a 9-minute analysis time that meets all method requirements.
Robust Rtx-DHA columns are highly stable and can be run with hydrogen carrier gas under accelerated conditions. The hydrogen-based method for detailed hydrocarbon analysis shown here is twice as fast as traditional approaches, which allows labs to process samples faster and make more profitable decisions during product blending.
Polar columns were evaluated for the analysis of fatty acids methyl esters (FAMEs) in finished B100 biodiesel according to method EN 14103 (2011). Using Restek’s Pro EZGC chromatogram modeler, a high cyano phase Rt-2330 column and a polyethylene glycol phase FAMEWAX column were compared. The modeling software predicted an unacceptable coelution between the internal standard (C19:0 FAME) and FAME C18:2 when using the Rt-2330 column. However, the modeler also predicted that the FAMEWAX column would separate all the compounds of interest, which was demonstrated empirically. In addition, the results on the FAMEWAX column showed excellent repeatability for both total FAMEs and the linolenic acid methyl ester component.
Restek’s Rtx-Volatile Amine column is specifically designed for GC analysis of volatile amines in challenging matrices. The stable bonded phase is highly retentive and selective for volatile amines to ensure good chromatographic separations and peak shapes. In addition, the column is very robust and able to withstand repeated exposure to harsh sample matrices, such as water.
Accurate analysis of biodiesel FAME in jet fuel is critical for ensuring that contamination levels do not exceed allowable limits. Method IP 585 is commonly used for this analysis and here we perform the method using a Stabilwax column and GC-MS in SIM mode. Method calibration curve criteria were met and good recoveries of the total FAME content in jet fuel were obtained.
Virtually unlimited in supply—but only available from Restek—new DiatoSorb-W diatomaceous earth offers a reliable alternative for packed column users. After years of dealing with supply shortages and inconsistent product quality, analysts who depend on diatomaceous earth columns now have a reliable new source. Restek now uses DiatoSorb-W as the exclusive replacement to the diatomaceous earth that was previously used in our standard and Silcoport W GC packed columns lines. All DiatoSorb-W material undergoes rigorous quality testing to ensure high purity and dependable performance. DiatoSorb-W material is available in acid-washed (WAW), non-acid washed (WNAW), and high-performance (WHP) varieties.
ASTM Method D2887 now allows for alternate carrier gases, so hydrogen or nitrogen can replace helium carrier gas for simulated distillation. Here, we show that with an MXT-1HT SimDist column and Restek’s EZGC online method translator existing methods using helium can be easily converted to either hydrogen or nitrogen carrier gas. Because retention times are preserved with proper method translation, there are minimal changes to peak identification tables which significantly simplifies method validation.
Increase lab productivity and confidence in your data. Featuring rugged Siltek-treated MXT tubing to eliminate breakage, all 5 m x 0.53 mm x 0.10 μm MXT-1HT SimDist columns from Restek (cat.# 70112) are tested up to 430 °C. Performance is guaranteed to meet ASTM Method D6352-12, D7169-11, and D7500-12 requirements.
Restek's porous layer open tubular (PLOT) columns feature an innovative bonding process that minimizes particle release, more consistent flow for stable retention times, and outstanding peak symmetry to improve impurity analysis. Restek PLOT columns are the benchmark for performance.
Rtx-DHA columns are ideal for Detailed Hydrocarbon Analysis (DHA) methods and easily meet or exceed both ASTM D6730-01 and Canadian General Standards Board CAN/CGSB 3.0 No. 14.3-99 requirements. Every Rtx-DHA column is tested for retention, efficiency, stationary phase selectivity, and bleed—guaranteeing reproducible column-to-column performance.
Carrier gas changes for SimDist methods, such as ASTM Method D7213, can be easily implemented in your daily process. Using MXT-1HT SimDist columns and EZGC method translation software, helium-based SimDist methods can be easily translated to alternative carrier gases while maintaining ASTM Method D7213 requirements.
Restek is your ideal partner for integrated petrochemical solutions, and our ASTM method product guide will help you quickly pick the right GC columns and reference standards for SimDist, DHA, finished gasoline, and other common petroleum analyses.
The current helium shortage has severely impacted gas chromatographers who are finding that helium has become significantly more expensive and is not always available when needed. This article explores the benefits and considerations of replacing helium with hydrogen carrier gas.
Comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOFMS) was used to analyze petroleum biomarkers creating unique fingerprints of crude oil samples and tarballs collected after the Deepwater Horizon oil spill.
Most analysts still use traditional packed columns for light hydrocarbon analysis, but many adsorbents are also available in micropacked column formats. Micropacked columns are a good alternative when both efficiency and sample loadability are desired.
Volatile amines, such as monomethylamine, diethylamine, and triethylamine, are widely used in the petrochemical industry, but are prone to poor peak shape and difficult to analyze. Low levels of volatile amines can now be accurately reported using new Rtx-Volatile Amine columns due to high column inertness.
Trace levels of sulfur compounds are separated and quantified by using an Rtx-1 capillary column or an Rt-XLSulfur micropacked column. The latter column is a specially deactivated porous polymer in Sulfinert-passivated stainless steel tubing.
Rt-XLSulfur columns resolve hydrocarbons from sulfur compounds in hydrocarbon process streams and exhibit excellent inertness with low ppbv levels of sulfurs.
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Restek's porous layer open tubular (PLOT) columns feature an innovative bonding process that minimizes particle release for more consistent flow, stable retention times, outstanding peak symmetry, and improved impurity analysis. Restek PLOT columns are the benchmark for performance.
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Rt-XLSulfur packed and micropacked columns combine a unique, efficient porous polymer packing material and true inertness toward active analytes, to ensure excellent and reliable results in trace-level analyses of hydrogen sulfide, sulfur dioxide, and other lightweight sulfur compounds.
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Rtx-DHA columns are ideal for Detailed Hydrocarbon Analaysis (DHA) methods and easily meet or exceed both ASTM D6730-01 and Canadian General Standards Board CAN/CGSB 3.0 No. 14.3-99 requirements. Every Rtx-DHA column is tested for retention, efficiency, stationary phase selectivity, and bleed—guaranteeing reproducible column-to-column performance.
Rt-Alumina BOND/MAPD columns offer higher capacity than other MAPD columns and are ideal for analyzing acetylene, propadiene, and methyl acetylene in petroleum gases. Greater capacity improves data accuracy due to better peak symmetry and a wide linear range.
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This 2-column set for modified ASTM Method D3606-10 completely resolves benzene from ethanol in reformulated fuels containing ethanol. The aromatic compounds also are fully separated and can easily be quantified using sec-butanol as an internal standard.
Impurity analysis of 1,3-butadiene on an Rt-Alumina BOND/MAPD column results in good separation of both light polar impurities (methyl acetylene, propadiene) and 4-vinylcyclohexene, a heavier contaminant that often requires testing on a second column.
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A ShinCarbon ST micropacked column will separate hydrogen, oxygen, nitrogen, carbon dioxide, carbon monoxide, and methane in 10 minutes, without cryogenic cooling. This 2-page note also shows separations of light hydrocarbon/permanent gas mixtures, natural gas components, and fluorocarbons.
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This flyer includes data demonstrating the performance of recommended GC columns for the analysis of total glycerin, fatty acid methyl esters (FAMEs), and residual methanol in biodiesel. Features a comparison of metal and fused silica columns.
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Rt- and MXT-Alumina BOND/MAPD PLOT columns outperform other MAPD columns for trace analysis of methyl acetylene, acetylene, propadiene, and other polar hydrocarbons. The new deactivation results in more predictable responses, increased capacity, and higher temperature stability.
Comprehensive 2D GC, also known as GCxGC, is a powerful technique with a great deal of potential for improving separations of complex petroleum and petrochemical samples that contain hundreds—or even thousands—of components. While GCxGC is still considered emerging technology and is used primarily in research and development labs, it has undergone significant growth in the past few years.
Rt-Alumina BOND/CFC columns provide high retention and high selectivity for volatile halogenated hydrocarbons, without the activity that is usually observed with alumina adsorbents. Chlorofluorocarbon analysis, in particular, can benefit from this new technology.
New metal MXT PLOT columns offer greater stability than conventional PLOT columns, making them a better choice for process GC analyzer applications. New bonding techniques result in highly reproducible flow characteristics, improved layer stability, and excellent separation efficiencies.
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Chromatograms, technical tips, and products developed specifically for petrochemical testing. Details recommendations for simulated distillation, PLOT column applications, DHA, D3606, biodiesel, permanent gases and hydrocarbons.
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Restek offers an expansive line of Sulfinert-treated sample cylinders, valves, and accessories.
Sulfur compounds in fuel streams can damage equipment and reduce BTU values. Sulfinert sample cylinders are significantly more inert than stainless steel cylinders and assure sample integrity during collection, transportation, and storage.
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When analyzing hydrocarbon impurities in propylene by ASTM D2712, using an Rt-Alumina BOND Na2SO4 PLOT column instead of a packed column setup provides the greatest degree of resolution in the least amount of time.
Using metal columns to analyze glycerides in biodiesel offer significant performance advantages compared to fused silica columns, as shown in this evaluation.
Refinery and natural gas samples often contain trace amounts of sulfur- and mercury-containing compounds, which can interfere with reactions, poison catalysts in petrochemical processes, and damage equipment. Because these compounds quickly react with stainless steel surfaces, accurate determination of these compounds is impossible when samples are collected and stored in untreated sample cylinders. Restek's Siltek and Sulfinert passivation techniques bond an inert layer into the surface of stainless steel, preventing active compounds from reacting with or adsorbing to the steel.
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When testing for impurities in ethylene using ASTM D6159-97, the combination of an Rt-Alumina BOND column coupled to an Rtx-1 column provides the best resolution of the most common hydrocarbon contaminants.
The high temperatures required for biodiesel analysis by gas chromatography present a considerable challenge to analytical columns. Fused silica columns, even those rated for high-temperature tolerance, breakdown relatively quickly. Restek’s new MXT-Biodiesel columns are more stable up to 430°C and offer excellent chromatography for glycerides. These columns are available in two configurations: factory-coupled to a 0.53mm retention gap, or with a built-in, leak-proof Integra-Gap retention gap.
The high temperatures required to analyze glycerol and glycerides as contaminants in biodiesel can result in shorter column lifetimes and more instrument downtime. Metal MXT-Biodiesel TG columns are more durable and last longer than their fused silica column counterparts, making them a better choice for labs wanting to minimize downtime. As demonstrated here, MXT-Biodiesel columns meet method EN 14105 (2011) performance requirements and provide excellent chromatographic results for biodiesel testing.
A Restek PLOT column can be your best solution for difficult separations of gaseous analytes. Rt-Msieve 5A PLOT columns offer fast, efficient separation of argon/oxygen, hydrogen/helium, and other permanent gases, including permanent gases in refinery or natural gas. You can make difficult separations without subambient temperatures, e.g.: separate oxygen from argon to baseline in approximately 4 minutes.
We challenged our Rtx-Biodiesel column with analysis for glycerin in biodiesel according to method ASTM D-6584-00. Excellent linearity was established for glycerin, triolein, monolein, and diolein, with r2 values exceeding the method criteria for all compounds. Mono-, di-, and triglycerides resolved well from other compounds in B100 biodiesel oil. Column performance was strong at high temperatures, with low bleed even at 380°C. An Alumaseal connector and guard column were used to extend column life.
Recovery of a 17ppbv test standard of hydrogen sulfide exceeded 85% after 54 hours in a Sulfinert-treated cylinder; recoveries of methyl mercaptan, ethyl mercaptan, carbonyl sulfide, and dimethyl disulfide exceeded 90%. A Sulfinert-treated sampling/transfer system can assure accurate sulfur content data for natural gas, beverage-grade carbon dioxide, or other samples.
Ultra-low bleed and exceptional inertness assure complete separation of sulfur compounds (hydrogen sulfide, carbonyl sulfide, dimethyl sulfide, mercaptans) on our new column, with excellent peak shapes and reliable quantification at ppbv levels. A Sulfinert treated sampling/transfer system assures no adsorption losses of these very reactive compounds.
Relative to helium as the GC carrier gas, hydrogen from a gas generator reduces gas costs, cuts analysis time by 50%, and reduces temperatures needed for eluting analytes which increases column lifetime. Parker ChromGas hydrogen generators are safe, convenient, reliable, and easy to use.
In process GC analyses, this material offers unique selectivity for the difficult-to-separate saturated and unsaturated C4 hydrocarbons, eluting cis-2-butene before 1,3-butadiene. Innovative bonding chemistry assures batch-to-batch reproducibility, excellent thermal stability, and long column life.
n-Octane on Res-Sil C packing provides excellent, reproducible separations of volatile hydrocarbons in petroleum products, including the difficult-to-separate saturated and unsaturated C4 compounds. An OPN on Res-Sil C column separates C1-C5 hydrocarbons in half the time required by alternative columns.
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ASTM D2887-01a is used to monitor petroleum products, excluding gasoline, with final boiling points of less than 538°C. Metal MXT-2887 columns and fused silica Rtx-2887 columns offer lower bleed, faster analysis times, and longer column lifetimes.
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Two methods are used to quantify individual alcohols and ethers in gasoline: a single column OFID method (e.g., ASTM Method D5599-94) and dual-column ASTM Method D4815-93. Restek offers columns, calibration mixtures, and inert capillary tubing for both approaches. 4-page note.
Restek's new D3606 column set outperforms TCEP columns for gasoline testing. The D3606 set has higher thermal stability and reliably resolves benzene from ethanol, resulting in more accurate quantitation.