Restek at Pittcon 2024

24-28 February, San Diego, CA, U.S.

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LEARNING LAB:

Simplify LC-MS/MS Method Development and Optimization for PFAS Analysis Using Restek’s Pro EZLC Chromatographic Modeler

Wednesday, February 28, 2:00 p.m.
Melinda Urich (presenter), Restek Corporation

Abstract
Restek’s free-to-use, Pro EZLC online chromatographic simulator allows users to select a compound list and instantly receive separation conditions that can be implemented directly in the lab. Choose from compounds found in several numbered methods, including EPA 1633, and workout your chromatography needs without touching an instrument, obtaining a column, preparing a mobile phase, or making a standard.

SHORT COURSES:

Practical Maintenance and Troubleshooting in Gas Chromatography

Monday, February 26, 8:30 a.m.–12:30 p.m.
Jaap de Zeeuw (presenter), CreaVision

Abstract
In gas chromatography, 90% of the trouble experienced happens within the injection system. In this course, we will discuss the purpose and impact of the critical parts (consumables) present in the split and splitless injections used in GC, and how their maintenance challenges affect a maintenance schedule. We will zoom in on carrier gas choice and purity, tubing, connections, septa, ferrules, seals, liners, column-coupling, installation, and column maintenance. Column operation/optimization and extending column lifetime will also be discussed along with the presentation of a series of practical examples via troubleshooting exercises.

Method Translation and Modeling in Gas Chromatography

Tuesday, February 27, 8:30 a.m.–12:30 p.m.
Jaap de Zeeuw (presenter), CreaVision

Abstract
In gas chromatography, there is often a wish to maximize uptime of instrumentation. This can be done using higher flows, different column dimensions, a different detector, or a different carrier gas. If you want to get the same peak elution order (same chromatogram), you must make sure that the elution temperatures of components are the same in the new method. This is only possible using a different oven temperature program. Additionally, it is now also possible to model separations for your analytes that allow you to change these parameters using your laptop. In this half-day course, we will discuss the basics of converting existing GC methods into a new (mostly faster or cheaper) method while aiming for the same separation/peak elution order. If column dimensions, linear velocity, or pressure drop secondary to a capillary column change without changing the temperature program, the separation of many components will change. Some separations will be better, some will be worse. In order to keep the peak elution order similar, you will need to adjust the oven temperature to get the same elution temperatures. We will also look at GC modeling that you can use for best separation of your components. Using a free, available online program, you can see the immediate impact of changing the carrier gas, changing the linear velocity, changing the stationary phase and column dimensions, changing the oven program, and switching from FID to MS and vice versa. We will do several live exercises. It is recommended to bring a laptop for the exercises

ORAL PRESENTATIONS:

Cannabinoid Extraction Efficiency for Potency Analysis: An In-Depth Look at Multiple Techniques

Sunday, February 25, 3:40–4:10 PM
Melinda Urich (presenter), Restek Corporation

Abstract
The cannabis market has a vast selection of extraction techniques available for cannabinoid potency testing. Many labs do not have the time or capacity to determine which technique best suits their needs. To assist with this gap, six unique extraction methods, varying from state agencies to regulatory bodies and different vendors, were investigated to determine extraction efficiency and to compare sample preparation cost and sample preparation time. To ensure comparable extraction efficiency across different varieties of flower, two types of chemovars were investigated, cannabidiol (CBD) dominant and cannabigerol (CBG) dominant. Due to its robust nature, a UV-Vis detector was used and monitored at 228 nm. A total of sixteen cannabinoids were monitored under isocratic conditions for a total cycle time of nine minutes.

Method Development for PFAS and Drugs of Abuse (DoA) Compounds Using a Virtual Method Development Tool

Monday, February 26; 10:10–10:30 a.m.
Samantha Herbick (presenter), Restek Corporation

Abstract
The development and optimization of Liquid Chromatography (LC) separations can be time-consuming and costly, often requiring many steps, including literature research, column selection, method scouting, method development, and method optimization. To reduce cost and save time, an instrument-free software modeling tool was developed. Users can select compounds from a database and instantly model a separation by adjusting parameters, such as instrument/system effects (dwell and extra column volume), temperature, and mobile phase additives.

A PFAS library containing 33 compounds and a DoA library containing 291 compounds were used to virtually develop methods. For each compound class, method parameters were selected within the software and virtual chromatograms generated. Generated method conditions were taken to the instrument and set up for analysis. To assess the accuracy of the modeler, experiments comparing compound retention time values between wet-lab and modeled data were conducted.

For LC method developers, novice or expert, who lack the expertise or the time to develop separations quickly and accurately, this novel, virtual method development software delivers a fast, no-cost starting point and can improve turnaround time, increase throughput to existing methods, and offer an on-demand consultative user experience.

Analysis of Mushroom Alkaloids and Their Metabolites Using a Bioinert Column by HPLC-UV

Tuesday, February 27, 10:00–10:30 a.m.
Melinda Urich (presenter), Restek Corporation

Abstract
Psilocin and psilocybin are tryptamine alkaloids found in a variety of plants and fungi. These compounds and other alkaloids are frequently found in psychedelic mushrooms, more commonly known as “magic” mushrooms. These are often used for their psychotropic effects, but microdosing has shown promise with the treatment of anxiety, depression, and other mental health disorders. With recent legalization in certain areas of the United States, labs are seeking to begin potency testing of psychedelic mushrooms and infused products. In this work, a low-cost, time-efficient method was developed and demonstrated on multiple matrices. Using a production lab environment, simple extraction procedures were established followed by dilution to prepare psilocybin-infused chocolates, gummies, extracts, and freshly ground mushrooms. Four of the endogenous alkaloids found in psychedelic mushrooms are phosphorylated and have tendencies to chelate with metal ions, causing poor peak shape, loss of sensitivity, and a shift in retention times. To rectify this, an inert Force Biphenyl 100 x 3.0 mm, 3 μm column with accompanying inert Force Biphenyl EXP Guard were chosen for analysis. Six analytes were monitored at 222 nm using a UV-vis detector and gradient method for a total cycle time of 7.5 minutes. Results demonstrated increased performance when compared to a stainless-steel column and guard.

Applications of Inert Biphenyl Stationary Phase in the Analysis of Mycotoxins and Other Fungal Alkaloids

Wednesday, February 28, 4:10–4:40 p.m.
Diego Lopez, Restek Corporation

Abstract
Stainless steel has been the preferred material to manufacture HPLC columns due to its ease of fabrication and mechanical resistance to pressure. Nevertheless, metal-analyte interactions are prevalent in the chromatographic device and may lead to poor peak shapes, low recoveries, and overall poor performance. This type of Non-Specific Adsorption (NSA) has been documented in the literature and several solutions has been commercialized in recent years to mitigate such interactions. Inert coatings via Chemical Vapor Deposition (CVD) offer one of the best solutions while enhancing the analyses of several acidic and chelating-prone species. In this study, we leveraged the biphenyl stationary phase with coated hardware towards the analysis of mycotoxins and psychedelic mushroom alkaloids. The inert biphenyl solution offered significantly higher sensitivity and peak areas without the need for chemical passivation or repetitive injections while mitigating the carryover of several highly adsorptive analytes (i.e., fumonisins and tenuazonic acid). Overall, the implementation of inert coatings in HPLC column hardware offer a robust and improved chromatographic performance without the need to alter already established methods and workflows. A survey of other LC passivating techniques will also be discussed.

TECHNICAL POSTERS:

New Capillary Gas Chromatography Column Optimized for Analysis of Semivolatiles

Tuesday, February 27, 10:00 a.m.–12:00 p.m.
Jessi Collier (presenter), Jana Hepner, Kristi Sellers, Whitney Dudek-Salisbury, Scott Adams, Jaap de Zeeuw, Chris English, Restek Corporation

Abstract
The US Environmental Protection Agency (EPA) developed a method for the analysis of semivolatiles using GC-MS/MS. This method allows the determination of on-column amounts of target compounds to be detected at orders of magnitude lower concentrations than conventional single quadrupole mass spectrometers. New column requirements include enhanced robustness, thermal stability, improved PAH selectivity, and extended lifetime following highly contaminated extracts. This presentation will show specific weaknesses of general-purpose 5-type columns for the analysis of environmental samples and the advantages of this new Rxi-SVOC column when used with tandem mass spectrometers.

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The Evolving Landscape of THC Drug Testing, Delta-8 vs. Delta-9

Monday, February 26, 1:00–3:00 p.m.
Jamie York (presenter), Haley Berkland, Restek Corporation

Abstract
When performing drug testing for THC, the carboxy metabolite is historically the analyte used to determine cannabis usage. This compound is detectable in urine or blood for several weeks, but it can be challenging to determine if a user is intoxicated at the time of testing. Labs may be interested in testing for the hydroxy metabolite, the intermediate between THC and the carboxy metabolite. This intermediate is useful in determining time of consumption. Delta8-THC is an isomer of delta9-THC that also has psychoactive effects. Chromatographic separation of delta8/9-THC and their respective metabolites is required due to their nearly identical structures. Three column chemistries were investigated in this study for the analysis of delta8/9-THC and their metabolites. Biphenyl, ARC-18, and FluoroPhenyl stationary phases were tested on a 100 x 2.1 mm column dimension using water and methanol as mobile phases, both modified with 0.1% formic acid. The FluoroPhenyl column shows great selectivity for the target analytes and resolved all three pairs of isomers with a 12-minute cycle time. This method could be used to determine THC isomers and metabolite levels in biological fluids.

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The Evolving Landscape of PFAS Detection, an Outline of Methods

Tuesday, February 27, 10:00 a.m.–12:00 p.m.
Jamie York (presenter), Restek Corporation

Abstract
Perfluoroalkyl substances (PFAS) are a group of man-made chemicals widely used in industrial applications and consumer products. Their widespread usage and resistance to degradation has resulted in PFAS being a ubiquitous environmental contaminant, and the potential health effects is of growing concern. While many of the long-chain PFAS have been recognized as harmful, alternative compounds have emerged in their place. Short-chain PFAS compounds are considered to be less bioaccumulative and toxic than long-chain PFAS, but their widespread use has resulted in their increased environmental accumulation. In this work, several methods will be outlined to meet the evolving landscape of PFAS analysis. These methods include EPA methods 1633, 533, 8327, and 537.1 as well as a method for the analysis of ultra-short through short-chain(C1-C4) PFAS using a unique hybrid HILIC/ion-exchange stationary phase.

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The Benefits of 2.1 mm Internal Diameter Analytical Columns for the Analysis of Drugs of Abuse by LC-MS/MS

Wednesday, February 28, 10:00 a.m.–12:00 p.m.
Samantha Herbick (presenter), Restek Corporation

Abstract
The biphenyl phase offers advantageous selectivity compared to a C18 column for drugs of abuse panels, but choosing the right column dimension is paramount to obtain robust and accurate data. Every column dimension can be advantageous in different scenarios, but generally clinical labs are all working towards the same goals: high throughput, low sample volume, good sensitivity, and low cost. We developed two methods to analyze common isobars in drugs of abuse panels on Raptor Biphenyl columns using methanol and water modified with 0.1% formic acid and column oven set to 45 ⁰C. These methods were compared for efficiency, sensitivity, resolution (Rs), consumption of mobile phase, and robustness. In this work, the advantage of the 2.1 mm ID column, which demonstrated superior sensitivity while consuming less resources and minimizing impact to the MS while still providing adequate resolution of isobars and excellent column robustness, is discussed and demonstrated for the analysis of drugs of abuse.

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