title: Simultaneous determination of four aflatoxins and ochratoxin A in ginger and related products by HPLC with fluorescence detection after immunoaffinity column clean-up and postcolumn photochemical derivatization.
abstract: Ginger, a widely used spice and traditional Chinese medicine, is prone to be contaminated by mycotoxins. A simple, sensitive, and reproducible method based on immunoaffinity column clean-up coupled with HPLC and on-line postcolumn photochemical derivatization with fluorescence detection was developed for the simultaneous determination of aflatoxins (AFs) B1 , B2 , G1 , G2 , and ochratoxin A (OTA) in 25 batches of gingers and related products marketed in China for the first time. The samples were first extracted by ultrasonication with methanol/water (80:20, v/v) and then cleaned up with immunoaffinity columns for analysis. Under the optimized conditions, the LODs and LOQs for the five mycotoxins were 0.03-0.3 and 0.1-0.9 μg/kg, respectively. The average recoveries ranged from 81.3-100.8% for AFs and from 88.6-99.5% for OTA at three spiking levels. Good linearity was observed for the analytes with correlation coefficients all >0.9995. All moldy gingers were contaminated with at least one kind of the five investigated mycotoxins, while none of them were found in normal gingers. Ginger powder samples were contaminated slightly with the contamination levels below the LOQs, while ginger tea bags were mainly contaminated by OTA at 1.05-1.19 μg/kg and ginger black tea bags were mainly contaminated by AFs at 3.37-5.76 μg/kg. All the contamination levels were below the legally allowable limits.
authors.affiliation: School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China; Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wen
authors.forename: Weijun
authors.initials: W
authors.lastname: Kong
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Meihua
authors.initials: M
authors.lastname: Yang
mesh_terms: D000348:Aflatoxins / Q000032:analysis* / Q000737:chemistry; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D005453:Fluorescence; D005506:Food Contamination / Q000032:analysis*; D005524:Food Technology / Q000379:methods*; D020939:Zingiber officinale / Q000737:chemistry*; D057230:Limit of Detection; D009793:Ochratoxins / Q000032:analysis* / Q000737:chemistry; D010777:Photochemistry; D015203:Reproducibility of Results
chemical_list: D000348:Aflatoxins; D009793:Ochratoxins; C025589:ochratoxin A
keywords: Aflatoxins; Fluorescence detection; Ginger; Ochratoxin A; Photochemical derivatization