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RAFA 2019

Recent Advances in Food Analysis (RAFA 2019)

Visit Restek at RAFA 2019
Visit Restek at RAFA 2019

VENDOR SEMINAR

TUESDAY, NOVEMBER 5
Aquarius Hall, 12:45-13:30
What Chemicals May Migrate into Your Food?
Prof. Erich Leitner, TU Graz, Graz, Austria

During this “Lunch and Learn” seminar, Prof. Erich Leitner from TU Graz will give a short introduction to European legislation regarding the migration of chemical compounds from packaging material into food. He will show the impact of NIAS and MOSH/MOAH on food quality and food safety with compelling examples, and he will also compare different analytical approaches for qualifying and quantifying migrated compounds in food samples.

In addition, Restek will offer a traditional Prague delicacy—served in sustainable biological packaging material—during this “lunchless” time of the conference.

For more information, email Hansjoerg Majer.

Preregister now

RESTEK TECHNICAL POSTERS

Food sample identification via Coated Blade Spray-High Resolution Mass Spectrometry
German Gomez1, Robert Cody2, Alexandria Pavkovich Bush1 (presenter), Dave S. Bell1
1. Restek Corporation, 2. JEOL Corporation
For more information, email Alexandria Pavkovich Bush.
Read abstract

Coated Blade Spray (CBS) is an SPME-based analytical technology that facilitates collection of analytes of interest from a sample and the direct interface to mass spectrometry systems via a substrate spray ionization. The device is comprised of a thin-flat sheet with a pointed tip and consists of a conductive substrate such as stainless steel. As a SPME device, the substrate is partially coated with an extraction phase comprised of polymeric particles and a binder. The function of the polymeric particles is to enrich the analytes of interest from the sample matrix, while collecting the least amount of matrix interferences. As a direct to MS device, this device requires a pre-wetting of the extraction material so to elute the analytes collected on it. Subsequently, a differential potential is applied between the non-coated area of the substrate and the inlet of the MS system, generating an electrospray at the tip of the CBS device. Herein, we demonstrate, as a proof-of-concept, how CBS coupled to High Resolution Mass Spectrometry (HRMS) enables rapid profiling of aqueous (i.e. beer) and solid food matrices (i.e. animal tissue). Unlike other ambient-ionization technologies, CBS allows you to perform sampling remotely, clean-up the sample, and retaining relevant chemical information that facilitates its classification via chemometric tools.

Beer samples from different types/manufacturers/world-regions were purchased at a local store. Samples (300 µL) were deposited on a 96-well plate and analyte collection was performed in high-throughput configuration (i.e. 96-CBS devices concomitantly) for 5 minutes. The discriminant analysis of principal components (DAPC) in combination with Kernel Principal Component Analysis (KPCA) allowed for adequate classification of each of the beer brands under evaluation. Further, when using 60 principal components (PC), the leave-one-out cross validation (LOOCV) and the Support Vector Machine (SVM) unequivocally identified each of the samples. Likewise, CBS was capable of differentiating different types of meat samples (e.g. lamb, beef, chicken, and pork). The DAPC-KPCA plot showed clear distinction of each meat. By using 60 PC, the LOOCV and SVM lead to a predictability of 94 and 96%, respectively. In a third experiment, CBS was used to differentiate diverse fish samples. The DAPC-KPCA plot showed clear distinction of each species. Similar to the meat samples, by using 60 PC, the LOOCV and SVM lead to a predictability of 94 and 96% of the fish samples, respectively.

Optimizing GC-MS and GC-MS/MS Analysis of 3-MCPD and Glycidyl Esters
Jana Rousova (presenter), Joe Konschnik, Hansjoerg Majer, Alexandria Pavkovich, Chris English
Restek Corporation
For more information, email Jana Rousova.
Read abstract

3-MCPD and glycidyl esters in edible oils are contaminants that are formed through refining processes and have been classified as possible human carcinogens. Methods have been developed by ISO, AOCS, and DGF for analyzing these contaminants. While these methods cover extraction and derivatization techniques in detail, very little attention is paid to the GC-MS analysis method. With emerging automated systems, it is important to simplify and speed up the instrument method by optimizing the parameters and switching to split injection.

Our initial optimization of the temperature program led to an 8-minute decrease in analysis time, however additional time can be saved by utilizing free method development software. The employment of split injection resulted in better peak shape and can achieved limits of detection that were comparable to splitless injection. Further evaluation of split injection revealed that performance similar to splitless injection can be achieved regardless of inlet temperature, which results in greater flexibility for different inlet configurations.

Analysis of Acylglycerols in Edible Oils by Gas Chromatography Using a Unique Stationary Phase
Joe Konschnik (presenter), Colton Myers, Kristi Sellers, Jana Rousova, Shawn Reese, Jaap de Zeeuw, Chris Rattray
Restek Corporation
For more information, email Joe Konschnik.
Read abstract

Characterization of edible oils is essential to the food industry due to the amount of fraudulent activity that surrounds these products. Some edible oils (e.g. Extra Virgin Olive Oil) carry high value, therefore making it an easy target for fraud. By mixing different vegetable oils (e.g. palm, sunflower, etc.) with high quality olive oils, manufacturers and suppliers increase their oil yields to make larger profits on counterfeit olive oils. For these reasons, it is important to obtain a triacylglycerol (TAG) fingerprint of edible oils to know that they have not been adulterated with other oils. In addition, the freshness of oils can be determined by looking at the ratio of 1,2 to 1,3-diacylglycerols (DAGs). By using a unique gas chromatography (GC) stationary phase without bleed interference and retention time shifting due to phase loss, one is able to resolve TAGs and DAGs, and a full analysis of the edible oil can be conducted for oil adulteration and degradation. The analysis and results for these oils will be presented along with an examination of column bleed at high GC operating temperatures.

Optimizing Sample Preparation for the Analysis of over 200 Multiresidue Pesticides in Produce by GC-MS/MS
Jana Rousova (presenter), Alexandria Pavkovich, Joseph Konschnik, Chris English
Restek Corporation
For more information, email Jana Rousova.
Read abstract

Optimization of sample preparation is an important step in mitigating matrix effects in the pesticides multiresidue workflow. Using the QuEChERS approach followed by dispersive solid phase extraction (dSPE) allows for customization of solutions based on matrices. In order to efficiently select the combination that yields the highest analyte response and provides sufficient clean-up, we first tested 40 representative pesticides with different QuEChERS salts and dSPE clean-up materials. The results were evaluated based on; the responses of all tested pesticides, responses of commodity relevant pesticides, and the overall cleanliness of the samples. To demonstrate the feasibility of developing optimized methods, organic celery and other representative matrices were spiked with over 200 pesticides at two levels, 100 ppb and 10 ppb. Non-spiked commodities were also analyzed for the presence of incurred pesticides. Separations were performed using a Rxi-5MS column (30 m x 0.25 mm x 0.25 μm) and analyzed by GC-MS/MS in selected reaction monitoring mode. Optimized sample preparation conditions, pesticide separations, and recovery results from organic celery, spinach, and other produce will be presented.

Quantitation of Mycotoxins in Four Food Matrices Comparing Stable Isotope Dilution Assay (SIDA) with Matrix Matched Calibration Methods by LC-MS/MS
Joe Konschnik (presenter), Dan Li, Justin Steimling, Ty Kahler
Restek Corporation
For more information, email Joe Konschnik.
Read abstract

Mycotoxins are secondary fungal metabolites produced by mold that may be found in food or feed. They can cause severe health problems in humans and animals, and can result in significant economic losses. Among the hundreds of toxic mycotoxins, aflatoxins, fumonisins, deoxynivalenol, ochratoxin A, HT-2 toxin, zearalenone, and T-2 toxin are considered as a major concern for corn, wheat, peanuts, and other agricultural products. LC-MS has become the standard and is now widely used for routine mycotoxin analysis and identification. One of the challenges faced by LC-MS techniques is the matrix effects caused by the use of electro-spray ionization (ESI). Generally, sample preparation, chromatographic and calibration techniques are the common strategies for reducing the negative effects of matrix effects. Standard addition, matrix matching, and stable isotope dilution assay (SIDA) are all possible calibration solutions. In this work, a quick “dilute-filter-shoot” method was used for sample preparation. A seven-minute LC-MS/MS method using a biphenyl phase column was developed and verified for quantifying twelve mycotoxins in four commodities: corn, peanut butter, brown rice, and corn & wheat mixed. Both SIDA and matrix matched calibration methods were applied, compared, and evaluated in terms of recovery, efficiency, advantages, and limitations.

The Analysis of Acrylamide Using an Aqueous Compatible Reversed-Phase Column by LC-MS/MS Detection
Landon A. Wiest (presenter), Paul Connolly, Joe Konschnik
Restek Corporation
For more information, email Landon Wiest.
Read abstract

Acrylamide is formed when substances containing asparagine and aldehyde sugars (i.e. glucose, fructose etc.) are roasted, fried, or baked at temperatures above 120 °C. The foods with the most acrylamide are roasted coffee and starchy foods such as potato chips, toasted bread, and cereal. Acrylamide is also found in drinking water that has been treated with polyacrylamide as a flocculating agent. Laboratory studies performed on mice show that high level exposure can cause reproductive harm, neurological defects ,and cancer. Accordingly, many methods have been developed to determine the amount of acrylamide present in foods, tobacco, and water. Multiple sample preparation techniques are effective at extracting acrylamide from matrix, but it is important to determine how much time should be invested on sample preparation and what stress the sample will place on your analytical system. QuEChERS-based methods tend to be quicker than SPE-based methods, but typically have more matrix components co-extracted which can lead to worse detection levels and more stress on your detector. SPE-based methods, result in a cleaner sample, but take a lot of time to prepare. LC columns used to quantify acrylamide often suffer from irreproducibility and poor column lifetimes. This results in longer turnaround times, less instrument uptime, and poor data quality. The Allure Acrylamide column addresses these pain points. This silica-based, aqueous compatible, reversed-phase column is part of a reproducible, retentive, and robust solution. The benefits of this column will be discussed showing examples of acrylamide separation from difficult matrices such as coffee and potato products. Particular emphasis on the role varying degrees of sample preparation will be discussed.

Optimizing a 190+ Pesticides Multiresidue Screening Workflow for the Preparation and Analysis of Produce by LC-MS/MS
Landon A. Wiest (presenter), Dan Li, Alexandria M Pavkovich, Joe Konschnik, Sue Steinike, Justin Steimling
Restek Corporation
For more information, email Landon Wiest.
Read abstract

Pesticides are ubiquitously used to help increase crop yields; however, they can pose health risks for the general public and pollinators. Faster multiresidue screening workflows, which combine easier sample preparation techniques that yield higher recoveries with lower instrument detection limits in fruits and vegetables, are often sought. Accomplishing these goals increases sample throughput, and reduces costs for laboratories and their clients. To demonstrate the feasibility of developing improved methods, organic celery and other representative matrices were spiked with pesticides down to 10 ppb. Samples were extracted using QuEChERS salts (AOAC 2007.01 and original unbuffered), and cleaned up with complementary dSPE containing MgSO4 along with appropriate amounts of C18, PSA and GCB sorbents for each matrix. Each sample was diluted 10x with water prior to analysis. Separations were performed with a sterically protected superficially porous C18 (Raptor ARC-18) column (100 mm x 2.1 mm, 2.7 µm) analyzed by a UHPLC-MS/MS in selected reaction monitoring mode. Optimized LC-MS/MS conditions, pesticide separations, and recovery (accuracy and precision) results from organic celery, spinach, orange, avocado, brown rice flour and honey will be presented.

The Detection of Fipronil and Fipronil Sulfone in Eggs
Jamie York1, Hansjoerg Majer2 (presenter), Landon A. Wiest2, Justin Steimling2, Ty Kahler2, Kevin A. Schug1
1. The University of Texas at Arlington 2. Restek Corporation
For more information, email Hansjoerg Majer.
Read abstract

Fipronil is a pesticide in the phenylpyrazole class and is used for a wide array of products, including some home flea and tick preventatives/treatments for household pets. The use of fipronil near animals for human consumption or laying hens is not permitted in Europe, as fipronil is fat soluble and could contaminate meat and chicken eggs. However, millions of eggs were destroyed last year due to illegal use of fipronil in Europe near laying hens, which resulted in the contamination of millions of eggs with the insecticide. Fipronil and its metabolite of similar toxicity, fipronil sulfone, inhibit the action of GABA in the central nervous system. Fipronil is more effective at blocking the GABA action in insects than in mammals, but fipronil sulfone is less selective. Once ingested fipronil can cause hypertension, paralysis, and death in insects and can cause indigestion, sweating, nausea, dizziness, agitation, vomiting, and seizures in humans. Because of the illegal use of fipronil around laying hens, it is crucial to develop a rapid, reliable, and sensitive method for detection of fipronil and its metabolite in eggs. In this study, we optimized methods for extraction of fipronil from eggs using QuEChERS. We also evaluated multiple HPLC stationary phases and developed an optimized method calibrated from 0.1 to 10 ppb.

The LC-UV Analysis of 16 Cannabinoids of Interest in Commercially Available CBD Oils
Hansjoerg Majer (presenter), Justin A. Steimling, Ty Kahler, Colton Myers, Ashlee Reese, Susan Steinike
Restek Corporation
For more information, email Hansjoerg Majer.
Read abstract

More than 100 cannabinoids have been isolated from cannabis in addition to the five most commonly tested: THC, THCA, CBD, CBDA, and CBN. While methods have been published that show the separation of these major cannabinoids, many do not take into account the possibility of interference from other cannabinoids that may be present. This is most problematic in concentrates where minor cannabinoids can be enriched to detectable levels that were not observed in the flower. Additionally, some terpenes have been shown to absorb UV light at 228 nm, the wavelength cannabinoids are typically detected, which can result in an additional source of interference. In this study, the LC-UV separation of 16 cannabinoids of interest was performed while monitoring for the potential impact from minor cannabinoids and terpenes on reported potency values. The method is applied to commercially available CBD oils that have recently become suspect due to inaccurate label claims.

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