title: Immunoaffinity column cleanup with liquid chromatography using postcolumn bromination for the determination of aflatoxins in black and white sesame seed: single-laboratory validation.
abstract: A single-laboratory validation was conducted to establish the effectiveness of an immunoaffinity column cleanup procedure followed by LC with fluorescence detection for the determination of aflatoxins B1, B2, G1, and G2 in sesame seeds. The sample is homogenized with 50% water (w/w) to form a slurry, then the test portion is extracted with methanol-water (60 + 40, v/v) using a high-speed blender. The sample extract is filtered, diluted with 15% Tween 20 in phosphate-buffered saline solution, and applied to an immunoaffinity column. Aflatoxins are removed with neat methanol, then directly determined by RP-LC with fluorescence detection using postcolumn bromination (Kobra cell). Test portions of blank white sesame seed slurry were spiked with a mixture of aflatoxins to give total levels of 4 and 10 microg/kg. Recoveries for individual and total aflatoxins ranged from 92.7 to 110.3% for spiked samples. Based on results for spiked sesame paste (triplicates at two levels), the RSD for repeatability (RSD(r)) averaged 1.1% for total aflatoxins and 1.4% for aflatoxin B1. The method was demonstrated to be applicable to naturally contaminated samples of black and white sesame seeds obtained from local markets in China.
authors.affiliation: Shenzhen Center for Disease Control and Prevention, No. 8 Long Yuan Rd, Shenzhen 518020, People's Republic of China.
authors.forename: Guihua
authors.initials: G
authors.lastname: Liu
authors.forename: Zhou
authors.initials: Z
authors.lastname: Zhu
authors.forename: Jinquan
authors.initials: J
authors.lastname: Cheng
authors.forename: Hamide Z
authors.initials: HZ
authors.lastname: Senyuva
mesh_terms: D000348:Aflatoxins / Q000032:analysis*; D002138:Calibration; D002846:Chromatography, Affinity / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D019075:Electrophoresis, Capillary / Q000379:methods; D005374:Filtration; D005504:Food Analysis / Q000379:methods; D054879:Halogenation; D007120:Immunochemistry / Q000379:methods; D007202:Indicators and Reagents; D057230:Limit of Detection; D012015:Reference Standards; D015203:Reproducibility of Results; D012639:Seeds / Q000737:chemistry; D031685:Sesamum / Q000737:chemistry*; D012997:Solvents; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D000348:Aflatoxins; D007202:Indicators and Reagents; D012997:Solvents