AOAC 133rd Annual Meeting - Final Program

Poster Abstracts | Monday

P-M-088 Guoyin Lai , Wenxuan Yuan , Dunming Xu , Zhigang Zhang , Xiamen Customs, Xiamen, China; Meiling Lu , Agilent Technologies (China) Co. Ltd, Beijing, China Reliable Determination of Food Additives in Various Food Matrices Using Ultra High Performance Liquid Chromatography Combined with Tandem Mass Spectrometry Coumarin and vanillin including alkylated vanillins are two important types of manmade food additives and they are widely applied in food industry to improve food taste features. However, due to the potential heath effect, these food addi- tives are regulated in young baby food strictly. Here a reliable method was developed for routine monitoring of these food additives in baby formula. Briefly, one gram of baby formula was mixed thoroughly with proper amount of acidified water following by extraction using acetonitrile. The extractant was exchanged into 10% aqueous methanol solution and further cleaned up by SPE cartridge. The methanol eluent was dried, re-dissolved, filtered and then subjected to LC-MS/MS analysis. It was found that the four analytes, coumarin, vanillin, methyl vanillin, and ethyl vanillin, exhibited excellent linear relationship within the concentration range of 15- 5000 µg/L. The S/N at the lowest calibration level ranging from 20 to 85. Spiking test at three levels of 50, 100, 500 µg/kg with 6 replicates at each level demonstrated excellent accuracy, with recovery ranging from 90.7 to 98.5% and RSD ranging from 0.74 to 3.76%. The method is accurate, precise, and reliable, and has the potential to extend to other food matrices with strict regulation on these food additives. Presenter: Meiling Lu, Agilent Technologies (China) Co. Ltd, Beijing, China, Email: mei-ling.lu@agilent.com TUESDAY, SEPTEMBER 10, 2019 Poster Presentation Viewing: 10:00am–5:00pm Author Presentations: 12:00pm–1:00pm AGRICULTURE AND ENVIRONMENT P-T-001 Laura Wood , Charles Barber , R. Gregory Downing , Rabia Oflaz , Rick Paul , Nicholas Sharp , U.S. National Institute of Standards and Technology, Gaithersburg, MD, USA Characterization of Biomass Reference Materials for Use in Environmental Research Biomass materials are increasingly used, whether alone or in combination with other fuels, as a means to reduce emissions pollution and ash in the environment and as a renewable energy source. Sales for biomass fuel designed for home use are also increasing both domestically and internationally. Regulatory requirements, international trade, and equipment longevity were drivers for the National Institute of Standards and Technology (NIST) to develop two Standard Reference Materials (SRMs) for biomass fuel in support of this industry. Analytical and sample preparation procedures for fuels such as coal are not suitable for the evaluation of wood biomass fuels, in addition, the existing

many insect fragments can be detected in foods using endpoint PCR? 5. Determination of decomposition in salmon products by mass spectrometry with sensory-driven multivariate analysis. Presenter: Heather Hawk, U.S. Food and Drug Administration, Jefferson, AR, USA, Email: heather.hawk@fda.hhs.gov P-M-086 Barry McCleary , Claudio Cornaggia , David Mangan , Ruth Ivory , Anna Draga , Tadas Kargelis , Artur Rogowski , Megazyme, Bray, Ireland Chemoenzymatic Synthesis of Novel Substrates for the Facile Measurement of Glucuronoyl Esterase Glucuronoyl esterases (GE) assist in delignification via hydro- lysis of the ester linkages between lignin polyphenol structures and glucuronoxylan present in hemicellulose. Given that these linkages contribute to the recalcitrance of lignocellulose, the discovery of new and improved GEs is an important target for the biofuel industry. A number of synthetic substrates to measure GE activity have previously been described but these generally lack sensitivity due to the absence of key structural features, notably a bulky alcohol group in the ester moiety, 4- O -methylation of the glucuronic acid residue and an α link- age between the glucuronic acid and the 2-position of xylose, that are all found in the native substrate. Building on these studies, we prepared a series of colourimetric oligosaccharide substrates which, when combined with two ancillary enzymes, namely a GH67 α -glucuronidase ( Geobacillus stearothermo- philus ) and a GH43 β -xylosidase (Selenomonas ruminantium ), form the basis of a colourimetric assay for glucuronoyl esterase. The structural requirements for a sensitive, selective, soluble assay substrate are elucidated in this study along with the chemoenzymatic preparation of these compounds. The develop- ment of the enzyme coupled assay format and its application to the measurement of GE in a range of industrial enzyme prepa- rations is also described. Presenter: Barry McCleary, Megazyme, Bray, Ireland, Email: barry@megazyme.com P-M-087 Jeff Wiseman , Jennifer Salmons , Mike Tanner , J2 Scientific, LLC, Columbia, MO, USA A Continued Evaluation of a Newly Developed Nitrogen Evaporator: Method Optimization and More Analytes To continue the evaluation a newly developed nitrogen evap- orator, recovery determinations were performed for analytes beyond our initial study of EPA Method 525 compounds. The unique features of this evaporator allow for a greater level of control over evaporation conditions. Method optimization will be explored taking into account solvent boiling points, nitrogen pressure at method stages and nozzle adjustment. Optimizing these conditions will result in higher throughput and better, more consistent recoveries for laboratories. Presenter: Jeff Wiseman, J2 Scientific, LLC, Columbia, MO, USA, Email: jwiseman@j2scientific.com

58 SEPTEMBER 6–12, 2019 SHERATON DENVER DOWNTOWN HOTEL