Pittcon 2018
Conference & Expo

Pittcon
Restek at Pittcon 2018

RESTEK TECHNICAL PRESENTATIONS


Monday, February 26, 8:30-12:30 p.m., Short Course Office W222, SC029
Short Course: Practical Maintenance and Troubleshooting in Gas Chromatography
Instructor: Jaap de Zeeuw
Restek Corporation
For more information, email Jaap de Zeeuw.
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In gas chromatography, 90% of the problems that occur are due to issues in the injection system. In this course, we will discuss the purpose and impact of the critical parts (consumables) present in split and splitless injection and how they affect a maintenance schedule. At the end, we will discuss a series of practical examples via troubleshooting exercises.

Monday, February 26, 3:45-4:05 p.m., Room 308A, 550-3
Oral Presentation: Gas Chromatographic Computer Modeling Software for Method Development
Jaap de Zeeuw (presenter), Scott Adams, Kristi Sellers, Linx Waclaski
Restek Corporation
For more information, email Jaap de Zeeuw.
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Our recently introduced EZGC modeling software is a selectivity tool that relies on a pre-loaded library of thermodynamic retention indices. This makes it possible to predict retention times and optimize chromatographic methods without the need to analyze compound sets under many different conditions. The program allows the user to select the stationary phase and simultaneously adjust film thickness, temperature, column length, column internal diameter, and flow rate. Users can enter compounds individually or cut/paste large lists of compounds into the program.

Since the introduction of EZGC modeling software, there have been thousands of searches across a broad range of compound classes. The program generates compound retention time, resolution, and peak width along with the column conditions and dimensions. A model chromatogram is provided to illustrate retention, peak width, and resolution. Users have the option to view compound mass spectral data with the added benefit of overlaying mass spectra for coeluting analytes. Specific searches can be saved and accessed at a later date. Examples of these features will be presented with a focus on challenging separations.

Tuesday, February 27, 8:30-12:30 p.m., Short Course Office W222, SC030
Short Course: Injection Techniques in Gas Chromatography
Instructor: Jaap de Zeeuw
Restek Corporation
For more information, email Jaap de Zeeuw.
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In gas chromatography the most important process is to get the sample into the column. If sample transfer is not optimized, the results will not be reliable. The goal of this course is to understand the different injection techniques used and the process by which a narrow injection band is obtained.

RESTEK TECHNICAL POSTERS


Wednesday, February 28, 1:00-3:00 p.m., Exposition Floor, Aisles 2000-2700
1600-9: New GC Inlet Liner Deactivation Exhibits Excellent Response for Active Compounds
Linx Waclaski (presenter), Scott Adams, Mark Badger, Jaap de Zeeuw, Kristi Sellers
Restek Corporation
For more information, email Linx Waclaski.
Download a PDF of the full presentation.
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The choice of an inlet liner is critical to GC analysts, since it impacts the quality of the chromatographic data. Inertness is one of the most important factors to consider, as active analytes can easily be degraded or adsorbed within a hot GC inlet. A new liner deactivation was developed with a high level of inertness towards sensitive compounds. This liner deactivation was tested with a variety of analytes, including various classes of pesticides, as well as acidic and basic probes. Other liner deactivations were also analyzed to compare performance for active compounds. Liners used in this study were single taper with wool and all injections were performed in splitless mode. This provides one of the most rugged assessments of deactivation quality.

1600-2: Techniques for Optimizing GC Analysis of Glycols in an Aqueous Matrix
Jaap de Zeeuw (presenter), Scott Adams, Corby Hilliard, Kristi Sellers, Linx Waclaski
Restek Corporation
For more information, email Jaap de Zeeuw.
Download a PDF of the full presentation.
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The analysis of ethylene glycol in water is a common test performed by food safety, chemical, and environmental laboratories. Many environmental samples originate from water runoff at airports, where ethylene glycol is used as a de-icing agent for airplanes during winter months. Because ethylene glycol is highly soluble in water, it is not easily concentrated by purge and trap. Therefore, the most frequently used sample introduction technique is direct aqueous injection. The direct aqueous injection of ethylene glycol is challenging because it can be difficult to attain reproducibility and good peak shape. The large expansion volume of water can cause backflash, carryover can cause inconsistent results, and excess water can extinguish the FID flame. These problems can prevent achieving the detection limit for ethylene glycol, which often is in the 1-10 ppm range. This study compares lifetimes of various polyethylene glycol (PEG) stationary phases under optimized conditions.

1600-10: The Importance of GC Inlet Liner Inertness
Linx Waclaski (presenter), Scott Adams, Mark Badger, Jaap de Zeeuw, Kristi Sellers
Restek Corporation
For more information, email Linx Waclaski.
Download a PDF of the full presentation.
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Introduction of analytes into a gas chromatograph typically occurs through a heated inlet that contains a glass liner. Inlet liners are deactivated to prevent unwanted interactions from occurring between the analytes and active sites commonly found in raw glass. These adverse reactions include chemical breakdown of reactive compounds as well as reversible and irreversible adsorption.

A new liner and wool deactivation has been developed with a high degree of inertness for many classes of compounds. This deactivation utilizes a vapor deposition process that results in a consistent coating with reproducible chromatographic results. The following work demonstrates the importance of using an inert inlet liner with repeatable performance from lot to lot. Examples of reactivity present in inlet liners will be presented and explored, emphasizing the benefits of the new liner deactivation.

Thursday, March 1, 10:00-12:00 p.m., Exposition Floor, Aisles 2000-2700
1900-3: Determining cis/trans Isomers in Fatty Acids by Gas Chromatography
Jaap de Zeeuw (presenter), Scott Adams, Colton Myers, Kristi Sellers, Linx Waclaski
Restek Corporation
For more information, email Jaap de Zeeuw.
Download a PDF of the full presentation.
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The United States Food and Drug Administration (FDA) requires disclosure of trans fat content of conventional foods and dietary supplements. Sample preparation for the most common methods involves derivatization of the hydrolyzed free fatty acids, converting them to methyl esters (FAMEs). Overall fatty acid composition can be determined with polyethylene glycol (PEG) capillary columns when double bonds of unsaturated fatty acids are mainly cis configuration. Separation and differentiation of cis/trans structures require highly polar columns containing biscyanopropyl stationary phases. This work examines FAMEs using a high-cyano containing capillary column by AOCS Method Ce-1j-07, AOAC Method 996.06, and other applications.


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