Foods, Flavors & Fragrances
The establishment of a 1 µg/g safety threshold for melamine in infant foods has led to a need for sensitive methods. Here we established GC/MS conditions for highly reproducible analyses and evaluated the effectiveness of both solvent-based and matrix-matched standards. Using this method, melamine and cyanuric acid were reliably detected at and below 1 µg/g in infant formula.
The method developed here provides a fast analysis of mycotoxins in peanut powder. Baseline separation of 12 FDA and EU regulated mycotoxins was achieved in a 5.5 minute analysis (7 minute total cycle time). This method can be applied to different matrices using either matrix-matched calibration or a stable isotope dilution assay. Sample throughput can be greatly increased by the short cycle time for each run.
The analysis of bisphenolic compounds that are used as alternatives to bisphenol A (BPA) is essential for monitoring exposure to and evaluating the safety of these emerging industrial chemicals. The LC-MS/MS method presented here provides excellent chromatographic peak shape and separation for an extensive list of BPA analogues in a fast, 8-minute analysis.
Complex, time-consuming immunoaffinity column sample prep protocols for mycotoxins can be replaced by this simple pass-through SPE sample cleanup. Paired with LC-MS/MS analysis using a Raptor Biphenyl column, excellent chromatographic results were obtained for aflatoxins and ochratoxins at 2 ng/g, providing a high-throughput solution for analyzing mycotoxins in cannabis.
Capillary GC is especially useful for determining total fat content, trans fat content, and total omega-3 polyunsaturated fatty acid content in foods. The choice of capillary column depends on the information required. As shown here, whatever your fatty acid analysis requirements, Restek can provide the consistent-performance analytical columns and reference mixes that will help you to accurately characterize your materials.
Featured Application: Multiresidue Pesticide Mix Extracted from Brown Rice Flour Using QuEChERS Extraction and Cleanup
Multiresidue pesticides analysis presents many challenges, from extensive lists of chemically diverse analytes to the negative effects of complex matrix components. The optimized chromatographic method described here allows the analysis of hundreds of compounds in as little as 7.5 minutes with a total cycle time under 10 minutes, ensuring fast, accurate sample screening and increased lab productivity.
This simple, isocratic LC-UV analysis of cannabinoids provides complete resolution of 16 cannabinoids, allowing accurate quantitative potency and profile data to be reported. All compounds are separated to baseline in a fast, 9-minute analysis, making this method suitable for high-throughput cannabis testing labs.
The analysis of melamine and related compounds is critical in protecting consumers from adulterated food products. While these highly polar analytes are difficult to retain and accurately quantify on many columns, the Raptor HILIC-Si column and LC-MS/MS method shown here allow quick and complete separations, so melamine and related compounds can be accurately identified and quantified even at residual levels.
Mycotoxin contamination of crops is not only a public health concern, but it also has a huge impact on the global economy. This highly selective LC-MS/MS analysis of 20 mycotoxins in just 9 minutes allows scientists to accurately identify toxins, to monitor food products for contamination, and to support control strategies that prevent economic loss.
Restek has optimized the manufacturing process and implemented a new, application-specific QC testing procedure for all new Rt-2560 columns (cat.# 13198). Here we demonstrate that, Rt-2560 columns produced using the optimized process exhibit excellent performance for both AOAC 996.06 and AOCS Ce 1j-07 FAMEs analysis and meet all method requirements.
Highly Reproducible Detailed cis/trans FAMEs Analysis Ensured by New Optimized Rt-2560 Column Manufacturing and Application-Specific QC Test
Even minor variations in manufacturing processes can potentially have detrimental effects on column-to-column reproducibility. As shown here, Rt-2560 GC columns produced using a newly updated and optimized manufacturing process exhibit high reproducibility and provide consistent performance for detailed cis/trans FAMEs analysis.
Raptor FluoroPhenyl columns perform well in both HILIC and reversed phase modes, giving method developers the flexibility to select the mode that performs best for their specific compounds of interest. Here we use a Raptor Fluorophenyl column in HILIC mode for LC analysis of 4-methylimidazole (4-MEI). This approach provides more retention than reversed phase mode and can be applied to determining 4-MEI levels in caramel colorings to monitor formulations and also in foods and beverages to assess potential exposure.
The use of antibiotics on food-producing animals is a public health and safety concern due to the potential of generating drug-resistant bacteria. A sensitive, efficient, and reliable analytical method for different classes of antibiotics is necessary to meet regulations covering maximum residue limits (MRL) for a variety of animal tissue and food products. The Raptor C18 LC column is the ideal choice for antibiotic residue analysis.
Despite the growing popularity of electronic cigarettes, relatively little work has been done to characterize their vapor. In this study, we developed a quick, simple thermal desorption device for sampling vapor, as well as methods for analyzing vapor and solutions to determine nicotine content (GC-FID) and impurity profiles (GC-MS). This novel approach, which utilizes an Rtx-VMS column, provides detectable levels of volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs) from a single 40 mL puff.
Analytical Method for Polycyclic Aromatic Hydrocarbons (PAHs) in Yerba Mate Tea Using Modified QuEChERS, Solid Phase Extraction and GC-TOFMS and GC-MS/MS
This application note describes the development of an analytical method for PAHs in tea that allows analysts to more quickly and accurately characterize target PAHs. Sample preparation is based on a modified QuEChERS extraction and solid phase extraction sample cleanup. Both GC-TOFMS and GC-MS/MS techniques were used and analyses were optimized for resolution of isobaric compounds, as well as for maintaining a reasonable analysis time.
High-Quality Analysis of Pesticides in Cannabis Using QuEChERS, Cartridge SPE Cleanup, and GCxGC-TOFMS
As medical marijuana is more frequently prescribed, patient safety must be ensured. Pesticide residue testing is an important part of assuring safe product is dispensed, but analysis can be extremely challenging due to matrix complexity. The use of QuEChERS, cartridge SPE cleanup, and GCxGC-TOFMS as presented here, produces high-quality quantitative data for this difficult analysis.
Prepare Olive Oil Samples for Pesticide Residue Analysis in Half the Time With a Fraction of the Solvent Using dSPE
Simplify and speed up sample preparation with Resprep dSPE tubes! Here we show the extraction and clean-up of pesticide residues from olive oil samples—twice as fast as GPC, with only a fraction of the solvent required for conventional SPE.
Stabilwax-MS Columns—Thermally Stable, High Polarity GC Columns for Flavor, Food, Fragrance, Industrial Chemical, and Solvent Analyses
Low-bleed Stabilwax-MS columns produce excellent results for the analysis of trace levels of polar compounds by GC-MS. These columns are ideal for a wide range of polar analytes including FAMEs, flavor compounds, essential oils, solvents, aromatics, acrolein/acrylonitrile, and oxygenated compounds. (PDF - 0kB)
HPLC Analysis of Glucosinolates in Vegetable Extracts without Ion Pairing Using an Ultra Aqueous C18 Column
Glucosinolates with hydrophilic functional groups are very difficult to retain by conventional reversed phase HPLC, and when the functional groups in a sample are diverse, polarity can differ widely, complicating the problem. Until now, reversed phase HPLC with an ion pairing reagent has been the inconvenient, but necessary, approach to these analyses. This 2-page note describes a column and conditions for analyses of glucosinolates, without ion pairing. (PDF - 0kB)
Evaluation of Dispersive and Cartridge Solid Phase Extraction (SPE) Cleanups for Multiresidue Pesticides in QuEChERS Extracts of Finished Tobacco Using GCxGC-TOFMS
We compared the efficacy of dSPE and cSPE cleanup methods for multiresidue pesticide analysis of QuEChERS extracts of finished tobacco products using GCxGC-TOFMS. Cleanup with dSPE tubes containing 7.5 mg of GCB and 25 mg of PSA produced better results than other methods, with average recoveries of 92% and 91% for 500 ppb and 50 ppb fortifications respectively.
Mitigating Matrix Effects: Examination of Dilution, QuEChERS, and Calibration Strategies for LC-MS/MS Analysis of Pesticide Residues in Diverse Food Types
LC-MS/MS is popular for monitoring pesticide residues in food due to its selectivity and sensitivity; however, matrix effects can cause poor data quality and difficult quantification. We evaluated the relative effectiveness of sample dilution, QuEChERS cleanup, solvent-based calibration, and matrix-matched calibration strategies to mitigate matrix effects in celery, kale, avocado, lime, and brown rice flour.
New Rxi-PAH GC Column; Resolve Important Isobaric Polycyclic Aromatic Hydrocarbons for Food Safety and Environmental Methods
Separate isobaric polycyclic aromatic hydrocarbons, including priority EFSA PAH4 compounds benz[a]anthracene, chrysene, benzo[b]fluoranthene, and benzo[a]pyrene, easily and accurately on an Rxi-PAH column. Whether you need more resolution or faster analysis, these new GC columns offer the selectivity and efficiency you need for food safety and environmental PAH analysis. (PDF - 0kB)
A Comprehensive Approach to Pesticide Residue Testing, Including Non-Target Analysis, for Fruits, Vegetables, and Nuts, Using QuEChERS, LC-MS/MS, and GCxGC-TOFMS
Food commodities that varied in water, fat, and pigment content were fortified with pesticides and processed using a QuEChERS sample preparation technique. Samples were analyzed by both GCxGC-TOFMS and LC-MS/MS, and good recoveries were obtained for most pesticides in most commodities.
Increase Data Quality for Sulfonamide Residue Analysis by HPLC and UHPLC Using Unique Biphenyl Column Selectivity
The unique selectivity and high retention of Biphenyl columns produce complete separation of sulfonamide residues and benefit both UV and MS detection. In addition, Biphenyl columns in a UHPLC format allow faster sample throughput when testing for these antibiotics.
Column selectivity has the most significant influence on chromatographic peak separation, or resolution, so choosing the right column can greatly speed up HPLC and UHPLC method development. In this article, we discuss column choice and identify a set of just 4 stationary phasesRestek’s USLC column setthat encompasses the widest range of reversed phase selectivity available today.
Comparing Pesticide Residues in Amish and Commercially Grown Strawberries and Spinach Using QuEChERS, Various dSPE Sorbents, and GC-TOFMS
QuEChERS extraction, dSPE cleanup, and GC-TOFMS analysis were used to assess pesticide residue levels in strawberry and spinach from both commercial and Amish growers. Various dSPE sorbent products were compared to determine which were most effective.
Determining Pesticides in Dietary Supplements with QuEChERS Extraction, Cartridge SPE, and GCxGC-TOFMS
The novel approach used here combines QuEChERS extraction, cartridge SPE cleanup, and GCxGC-TOFMS analysis, resulting in good recoveries for a wide range of pesticides in dietary supplements. Matrices include dandelion root, sage, and a multi-herb finished product.
Analysis of pesticide residues in foods is complicated by the large number of target compounds. LC-MS/MS analysis using an Aqueous C18 column provides more comprehensive results than GC alone.
QuEChERS is a simple, effective approach to sample prep that can be applied to the analysis of pesticides in dietary supplements. Here, we demonstrate a QuEChERS, cSPE, GC-TOFMS procedure that results in good recoveries for a wide range of pesticides in dandelion root. (PDF - 0kB)
QuEChERS dSPE methods simplify extract cleanup, reduce material costs, and improve sample throughput. Here we demonstrate the effectiveness of QuEChERS sample cleanup using a multiresidue analysis of pesticides on strawberries. (PDF - 0kB)
Thermal desorption offers an automatic, high-sensitivity alternative to conventional liquid extraction methods for aroma profiling by GC/MS. It allows vapor profile constituents to be cleanly separated from the sample matrix and often facilitates selective purging of volatile interferences. This ensures that the vapor profile analyzed is most representative of the aroma perceived by consumers and that key compounds can be identified and measured at the lowest levels possible.
EPA Method 531.1 addresses the analysis of carbamate pesticides in water, but not in more complex matrices, which often contain interferences and require time-consuming sample preparation. We developed an easy, accurate screening method for carbamates in a complex matrix using an Ultra Carbamate HPLC column in conjunction with the Leco Unique TOF- MS. This method requires no sample preparation and provides fast analysis times, significantly increasing sample throughput.
Melamine contamination was implicated in a large pet food recall that occurred in 2007 when animals died after eating contaminated pet food. Here, a modified GC/MS method, based on an FDA method, was used to analyze for melamine & related compounds cyanuric acid, ammelide, and ammeline in dry cat food. Analytes were easily identified by retention time matching and mass spectra.
Chromatographic methods for garlic and garlic powder are used by the food and dietary supplement industries to monitor product quality. Here we present a headspace gas chromatography mass spectrometry (HS GC/MS) method for garlic flavor and odor components using an Rxi-5ms column. This method eliminates sample preparation making the bench work simple and fast. The experimental set-up is ideal for both screening analysis and low-level trace analysis.
Nitrofurans are a class of veterinary antibiotics used to increase growth rate and prevent or treat disease in animals. Determining levels of nitrofurans in animal tissue, or even products such as honey, is important in studying drug resistance and allergies in humans. The Ultra C18 HPLC column is an excellent choice for LC-MS/MS analysis of nitrofurans at low levels in complex matrices such as honey. Here we show excellent sensitivity, resolution, and peak shape at trace levels.
Commonly used organic acid methods (e.g. AOAC method 986.13) depend on reversed phase HPLC and C18 columns, however these columns are vulnerable to phase collapse when used with the aqueous mobile phases necessary for optimal organic acid analysis. Restek’s Ultra Aqueous C18, Allure Aqueous C18, and Allure Organic Acids columns all withstand phase collapse and resolve organic acids in a 100% aqueous mobile phase, compared to a conventional C18 column which shows a complete loss of retention.
An Ultra Aqueous C18 column enables you to use the conditions most effective for this analysis: gradient elution in high aqueous mobile phases. The C18 chains will not collapse in the presence of a high water content. Use this chromatographic system to extract data for specific compounds of interest and to manually inspect spectra for phenolic glycosides, esters of phenolic acid, or other compounds.
Quick, Easy, Cheap, Effective, Rugged, and Safe, the QuEChERS ("catchers") method for extracting pesticides from food is based on USDA research and employs a novel dispersive solid phase extraction cleanup (dSPE). QuEChERS methods are convenient, rugged methods that simplify extract cleanup, reduce material costs, and improve sample throughput. Here we demonstrate the effectiveness of QuEChERS sample cleanup using a multiresidue analysis of pesticides on strawberries.
Conditions are established for analyzing both derivatized and underivatized cholesterol on a highly inert Rxi-5ms column. Methods described include both an isothermal analysis for use when interferences are minimal, but sample throughput is critical, and a temperature program for use when separation of analytes from contaminants or interfering compounds is the primary concern. Results for both derivatized and underivatized samples were highly reproducible.
We separated flavonoids in cacao or cocoa powder samples and returned conditions to the initial mobile phase composition in 15 minutes. For compounds common to both samples, retention times were equal to within 0.01 seconds. Flavonoid marker compound profiles for 38%, 49%, and 65% cacao were easily distinguished.
Illegal use of malachite green (MG), an inexpensive fungicide, can allow MG to enter water cycles, where it is easily absorbed by fish tissue, and thus enters the human food supply. Reversed phase HPLC often is used to analyze for MG and its stored metabolite, leucomalachite green. Methods that facilitate detection of both compounds are discussed.
Thermal desorption is used extensively for measuring volatile and semivolatile components in foods, flavors, fragrances, and odors. This 28-page publication from Markes International Ltd. presents several key applications. (PDF - 0kB)
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