AOAC 133rd Annual Meeting - Final Program

Poster Abstracts | Tuesday

DETECTION AND MEASUREMENT OF NATURAL TOXINS P-T-047 Kai Zhang , U.S. Food and Drug Administration, College Park, MD, USA Application of an Automated Sample Preparation System for Mycotoxin Analysis in Foods Interest in replacing manual operations using robotic tools justi- fies the need of automation systems that can handle repetitive and high-volume tasks. For food analysis, automated sample preparation is still in its early stage, though such practice have been commonly used in areas of drug screening. For food analysis, samples need to be processed prior to instrumental measurements through multiple steps. This makes automated sample preparation a challenge as each step requires different tools, labware, and sample vessels. A highly automated sample preparation workflow requires integration of required devices and capability of transportation and storage so that samples can be processed and moved through each sub-step. In this proof of concept study, an automation system was evaluated, focus- ing on sample preparation for the determination of mycotoxins using LC-MS. The system is equipped with two robotic arms, various modular tools and storage racks, and can conduct trans- port, gravimetric and volumetric dispensing, shaking, capping/ decapping, filtration, and centrifugation without human assis- tance. Fortified corn, peanut butter, milk, and certified reference materials were used to evaluate the performance of the system. Our results suggest that automation is a promising alternative to manual operation and has potential applications in areas of food analysis. Furthermore, automation could help laboratories achieve a high degree of standardization for routine mycotoxin analysis. Presenter: Kai Zhang, U.S. Food and Drug Administration, College Park, MD, USA, Email: kai.zhang@fda.hhs.gov P-T-048 Jingping Xie , Titan Fan , Beacon Analytical Systems, Inc., Saco, ME, USA Determination of Tenuazonic Acid in Ketchup, Tomato Juice, Fresh Tomato, Apple, and Citrus by Immunoassay Alternaria species produce more than 70 secondary metabo- lits, but only a few of them have been reported as mycotoxins. Tenuazonic acid (TeA) is considered to have the highest acute toxicity among the Alternaria mycotoxins. A competitive immu- noassay was developed for the quantitative determination of TeA in tomato ketchup, tomato juice, fresh tomato and citrus fruit samples. Rabbit polyclonal antibodies against TeA were produced and the limit of detection was 1 ppb with the detection range from 1 to 100 ppb. Total assay time was 1 hour. Ketchups, citrus juice and tomato juice were extracted with 2 times volume of ethyl acetate, vortex 1 minute and centrifuge 5 at 4000 rpm. The 0.2 ml of ethyl acetate supernatant was dried at 40°C heating block and analyzed by the immunoassay after it was reconstituted with 0.5 ml of 10% methanol/PBS. Tomato ketchup (2 g) was diluted with lab grade water (4 ml) and 2 ml diluted sample was extracted with 4 ml ethyl acetate. TeA was spiked in ground fresh tomato, apple, orange, tomato juice and ketchup.

The recoveries were 85-108%. A total of 24 tomato-based and citrus-based products collected in the United States and Canada supermarkets were analyzed for the TeA by ELISA. No toxins were found in fresh tomatos, citrus samples, apple cider and apple sauce. Two of the ketchup samples showed over 100 ppb TeA (107 and 185 ppb). Repeat tested the 185 ppb ketchup sample with spiked 300 ppb of TeA and recovery from spiked of 300 ppb was 86%. Presenter: Jingping Xie, Beacon Analytical Systems, Inc., Saco, ME, USA, Email: jingping@beaconkits.com P-T-049 Deepali Mohindra , Thermo Fisher Scientific, Sunnyvale, CA, USA; Sylvia Grosse , Mauro de Pra , Frank Steiner , Thermo Fisher Scientific, Germering, Germany Determination of Underivatized Aflatoxins B2, B1, G2, and G1 in Ground Hazelnuts by Immunoaffinity Solid- Phase Extraction with HPLC-FLD Detection Mycotoxins are naturally occurring fungal toxins that are typi- cally not destroyed during processing or cooking procedures. One common group are the aflatoxins, of which 20 naturally occurring forms are known. Aflatoxin B1 is considered to be the most toxic to human health; the aflatoxins B2, G2, G1, and the milk-derived derivatives M1 and M2 are also considered important and are regulated for their levels in food by the European Commission. The focus of this application is the deter- mination of the toxins B2, B1, G2, and G1 in ground hazelnuts. The maximum level for aflatoxin B1 ranges from 2 to 12 μg/ kg for foods used for direct consumption or as an ingredient; baby food products have a maximum level of 0.10 μg/kg. The limit sum of all four aflatoxins varies between 4 and 15 μg/kg. Fluorescence derivatization is often used to achieve the sensitiv- ity required, however the challenge of incomplete derivatization is always present. Here we describe the use of immunoaffinity solid-phase extraction followed by underivatized fluorescence detection to give sufficient trace level detection performance for the European Commission limits. Presenter: Deepali Mohindra, Thermo Fisher Scientific, Sunnyvale, CA, USA, Email: deepali.mohindra@thermofisher.com P-T-050 Elizabeth Manning , Joyce Wilcox , Namoi MacKay , Monika Pazdanska , Ria Rhemrev , R-Biopharm Rhône Ltd, Glasgow, United Kingdom Analysis of Spices Using IMMUNOPREP ® Online Ochratoxin Cartridges Ochratoxin A is produced by moulds of the genera Aspergillus and Penicillium . Such fungi thrive in a warm damp environment. Food and feed are susceptible to fungal contamination during growth, harvest and storage. Ochratoxin can be found in a wide range of food commodities including spices and coffee and European legislative levels are currently in place. in terms of analysis, immunoaffinity clean-up is already well estab- lished in Official Methods (AOAC INTERNATIONAL and CEN Standards) for use in the analysis of a diverse range of complex matrices for all the regulated mycotoxins including aflatoxins and ochratoxin A. These immunoaffinity column methods have been rigorously validated and have been applied to a variety of spice

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