AOAC 133rd Annual Meeting - Final Program

Poster Abstracts | Wednesday

P-W-024 Robert Shirey , Stacy Shollenberger , Katherine Stenerson , MilliporeSigma, Bellefonte, PA, USA The Measurement of the Effects of Container Materials on Production of Light Induced Off-Flavors in Milk Using Solid Phase Microextraction (SPME) Gas Chromatography-Mass Spectroscopy It has been well documented that when milk is exposed to UV light, off-flavorings are produced. Ultra-Violet (UV) light causes a free radical reaction with unsaturated fatty acids, primarily linoleic acid, forming hydroperoxides that readily oxidize mostly to pentanal and hexanal. Because of their low sensory threshold, these malodors are readily detected in milk products. Other UV induced malodors are sulfides formed from the degradation of sulfur-containing amino acids. Dimethyldisulfide and dimethyl sulfide are the primary products of this reaction. The presence of these products was readily observed with the transition from glass to plastic milk storage containers. In this study, milk was place in similar sized containers made from both glass and a variety of plastic materials. The containers were then exposed to fluorescent lighting for a fixed time. The flavors and off-flavors in the exposed milk were extracted using headspace SPME with a Carboxen-PDMS coated Nitinol fiber followed by analysis using GC-MS. This fiber coating retains low molecular weight analytes, and allowed detection in the samples at concentration levels less than 1 ng/mL (ppb). The major flavoring contaminants were quantified in milk samples stored in the various contain- ers. This presentation will show the differences between storage containers and the effectiveness of SPME to identify and quantify the off-flavors formed in the milk samples. Presenter: Katherine Stenerson, MilliporeSigma, Bellefonte, PA, USA, Email: katherine.stenerson@milliporesigma.com P-W-025 Joseph Konschnik , Dan Li , Justin Steimling , Ty Kahler , Restek Corp., Bellefonte, PA, USA Quantitation of Mycotoxins in Four Food Matrices Comparing Stable Isotope Dilution Assay (SIDA) with Matrix Matched Calibration Methods by LC-MS/MS 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 prepa- ration, 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 quantify- ing twelve mycotoxins in four commodities: corn, peanut butter, brown rice, and corn and wheat mixed. Both SIDA and matrix

ranks on the market? COFFEE AUTHENTICITY: Does the actual composition of the coffee I usually drink match what is indi- cated on the label? Do I know the geographical origin of my product? COFFEE SUSTAINABILITY: Was capsules composta- bility considered? What is the end of life of these products? The answer to all these questions includes a deep knowledge of the subject, cutting-edge equipment and a long scientific experience to provide SUITABLE and SUSTAINABLE tools. This poster presents a case study related to NIAS (Non-Intentional Added Substances) detection, a test performed by Mérieux NutriSciences thanks to the most advanced analytical tech- niques in mass spectrometry: it allowed the identification of tetrahydrofuran (a molecule which does not exist in nature) as a (NIAS) degradation product of 1,4-butanediol contained in compostable coffee capsules. Presenter: John Szpylka, Mérieux NutriSciences Corp., Crete, IL, USA, Email: john.szpylka@mxns.com P-W-023 Yu-Cheng Lai , Yu-Ning Shih , Taiwan Food and Drug Adminstration, Taipei, Taiwan Integration of Analytical Methods for Inorganic Arsenic in Food Arsenic and inorganic arsenic are regarded as Class I carcino- gens by IARC (International Agency for Research on Cancer). Inorganic arsenic can be divided into arsenite (AsIII) and arsenate (AsV). However, arsenite is more toxic than arse- nate. Rice and seaweed may accumulate arsenic due to the contaminated environment. To safeguard public heath, TFDA has actively developed and integrated the analytical method on the speciation of arsenic in food by using acid extraction and then being analyzed by high performance liquid chromatogra- phy coupled to inductively coupled plasma mass spectrometry (HPLC/ICP-MS). The samples were homogenized and accu- rately weighted into polypropylene centrifuge tubes and 0.28 M HNO 3 solution was added. Then, the samples were extracted in an ultrasonic bath at 80 ° C for 60 mins. After cooling, the samples were adjusted to a constant volume by 0.28 M HNO 3 solution. The separation of all arsenic species was performed on a PRP-X100 anion exchange column (4.6 × 150 mm, 5 μm). After separating, ICP-MS was operated in helium collision mode to detect arsenic at m/z 75. The calibration curves had coeffi- cients of determination above 0.995. The recoveries of inorganic arsenic from certified reference materials NIST-SRM ® 1568b and NIMJ-CRM ® 7405a were 99.6 and 104.2%, respectively. The analytical method had a quick and simple pretreatment, and it could provide a feasible and fast way to analyze inorganic arsenic in rice and seaweed simultaneously. Presenter: Yu-Ning Shih, Taiwan Food and Drug Adminstration, Taipei, Taiwan, Email: yuning520@fda.gov.tw

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