Determination of Aflatoxins and Ochratoxin A in Traditional Turkish Concentrated Fruit Juice Products by Multi-immunoaffinity Column Cleanup and LC Fluorescence Detection: Single-Laboratory Validation

Single laboratory method validation was conducted to establish the effectiveness of a multi-immunoaffinity column cleanup procedure followed by liquid chromatography (LC) with fluorescence detection for the determination of aflatoxins B1, B2, G1 and G2 and ochratoxin A in two traditional Turkish concentrated fruit juice products (pekmez and pestil). The homogenized sample is extracted with methanol-water (80+20) using a high-speed blender. The [sample] extract is filtered, diluted with phosphate buffered saline solution (PBS) and applied to a multi-immunoaffinity column (AFLAOCHRA PREP®). Aflatoxins and ochratoxin A are removed with [neat] methanol, and then directly analyzed by reversed-phase LC with fluorescence detection using post-column bromination (Kobra cell®). Test portions [of pekmez and pestil] were spiked with a mixture of aflatoxins and ochratoxin A to give levels ranging from 2.5-10.0 µg/kg and 1.0-4.0 µg/kg respectively. Recoveries for total aflatoxins and ochratoxin A ranged from 84-106% and 80-97% respectively for spiked samples. Based on results for spiked pekmez and pestil (30 replicates each at three levels) the relative standard deviation for repeatability (RSDr) ranged from 1.6-12% and 2.7-11% for total aflatoxins and ochratoxin A respectively. The method was demonstrated as being applicable to naturally contaminated samples of pekmez and pestil obtained from local markets in Turkey.

KAYMAK Tugrul;  TÜRKER Levent;  TULAY Hüseyin;  STROKA Joerg; 

2019-02-27

AOAC INT

JRC114710

1060-3271 (online),   

https://www.ingentaconnect.com/content/aoac/jaoac/2018/00000101/00000006/art00020,    jsessionid=csbmh4sd2d2j1.x-ic-live-01,    https://publications.jrc.ec.europa.eu/repository/handle/JRC114710,   

10.5740/jaoacint.17-0463 (online),