Publications by authors named "Philip Wylie"

A method has been developed to screen cannabis extracts for more than 1,000 pesticides and environmental pollutants using a gas chromatograph coupled to a high-resolution accurate mass quadrupole time-of-flight mass spectrometer (GC/Q-TOF). An extraction procedure was developed using acetonitrile with solid phase extraction cleanup. Before analysis, extracts were diluted 125:1 with solvent.

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Background: Neonatal alloimmune thrombocytopenia (NAIT) commonly arises due to antibodies against a small number of well-defined human platelet antigens (HPAs). A minority of NAIT cases occur due to maternal immunization against low-frequency polymorphisms in platelet glycoprotein that result in new immunogenic epitopes. Antibodies to these novel epitopes can be detected by the incubation of maternal serum with paternal platelets and is usually performed after initial investigation using HPA-typed panel platelets has failed to provide evidence of NAIT.

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Correct identification of the true bay leaf () and its substitutes is important not only for the quality control of the products, but also for the safety of the consumers. is often substituted or confused with other species, such as , and In the present study, the potential of gas chromatography combined with quadrupole time-of-flight mass spectrometry for the profiling of various bay leaf products was evaluated for the first time. Thirty-nine authenticated samples representing the true bay leaf and the four commonly substituted species were analyzed.

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Methoxypyrazines are volatile compounds found in plants, microbes, and insects that have potent vegetal and earthy aromas. With sensory detection thresholds in the low ng L(-1) range, modest concentrations of these compounds can profoundly impact the aroma quality of foods and beverages, and high levels can lead to consumer rejection. The wine industry routinely analyzes the most prevalent methoxypyrazine, 2-isobutyl-3-methoxypyrazine (IBMP), to aid in harvest decisions, since concentrations decrease during berry ripening.

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For the first time in the literature, application of a GC-ICP-MS/MS method for the selective and sensitive detection of specific heteroatoms of phosphorus, sulfur, and chlorine has been accomplished. As a proof of concept, organophosphorus, organosulfur, and organochlorine pesticides in various food matrices have been studied. For the detection of organophosphorus and organosulfur pesticides, oxygen was used in the collision reaction cell (CRC) to convert P (m/z 31) to PO(+) (m/z 47) and S (m/z 32) to SO(+) (m/z 48).

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A high-resolution gas chromatography/mass spectrometry (GC/MS) with selected ion monitor method focusing on the characterization and quantitative analysis of ginkgolic acids (GAs) in Ginkgo biloba L. plant materials, extracts, and commercial products was developed and validated. The method involved sample extraction with (1:1) methanol and 10% formic acid, liquid-liquid extraction with n-hexane, and derivatization with trimethylsulfonium hydroxide (TMSH).

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As part of an ongoing research program on authentication, safety and biological evaluation of phytochemicals and dietary supplements, an in-depth chemical investigation of different types of chamomile was performed. A collection of chamomile samples including authenticated plants, commercial products and essential oils was analysed by GC/MS. Twenty-seven authenticated plant samples representing three types of chamomile, viz.

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There is interest in reducing pesticide residues in fruits and vegetables in order to minimize human exposure. The objectives of this study were to (i) determine the effect of various washing treatments with and without sonication on pesticide removal from tomatoes and (ii) assess the effectiveness of a water wash on select samples using a produce-washing flume. In the first set of experiments, tomatoes were contaminated with acephate, malathion, carbaryl, bifenthrin, cypermethrin, permethrin, cyhalothrin, chlorothalonil, and imidacloprid and were dried overnight.

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This study evaluated the use of a new concurrent backflushing set-up in the multiresidue analysis of pesticides in dietary supplement matrices using gas chromatography-tandem mass spectrometry (GC-MS/MS). The backflushing configuration employed a purged union installed between a short, 5-m long capillary column and a 15-m analytical column of the same column diameter (0.25 mm i.

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A full-scan GC/quadrupole/MS method has been developed to perform large-scale screenings of pesticides and simultaneous quantification of 95 target compounds in a single run of 21 min. The screening method was performed by using a deconvolution of the spectrum of the full-scan data files acquired under a retention time locked method. The identification performance of the screening method was evaluated in eight different food matrixes at three different concentrations.

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