Liquid chromatography incorporating ultraviolet and electrochemical analyses for dual detection of zeranol and zearalenone metabolites in mouldy grains.
BACKGROUND
Zeranol (Z) is a semi-synthetic mycotoxin that is used in some countries as a growth-promoting agent in livestock. In view of the known oestrogenic actions by Z and certain Z analogues, significant concerns exist with regard to the presence of Z residues in human foods and the potential for untoward effects, including carcinogenicity within the reproductive system. In order to confirm that foods are free from harmful Z residues, regulators need a quick and reliable analytical method that can be used for routine confirmation of Z-positive samples identified by enzyme-linked immunosorbent assay (ELISA) screening. In this study the authors have developed and validated a simple and rapid high-performance liquid chromatography method incorporating ultraviolet (UV) absorbance (wavelength 274 nm) and electrochemical (EC) dual-mode detection for simultaneous determination of Z-related mycotoxins produced from mouldy grain matrices, including rice, soybean and corn flakes.


RESULTS
Recoveries for all analytes were around 80% and the limits of detection ranged from 10 to 25 ng mL(-1) for UV and from 50 to 90 ng mL(-1) for EC detection with good accuracy and reproducibility. Differential profiles and occurrence rates of Z, β-zearalenol, β-zearalanol and α-zearalenol in naturally moulded grain matrices were observed, indicating different metabolite patterns and possibly grain-specific effects of mycotoxin exposure for humans and animals. The strength of this dual detection method lies in its selectivity characterised by a carbon screen-printed electrode such that aflatoxin interference is precluded.


CONCLUSIONS
The combined dual detection technique affords quick and reliable semi-confirmative and quantitative information on multiple types of Z analogues in mouldy grains without the necessity of using expensive mass spectrometry. The method is considered a superior supplement to ELISA, which only screens total Z immunoreactivity.
Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung 402, Taiwan.
Han-Yun
HY
Hsieh
Ching-Lin
CL
Shyu
Chen-Wei
CW
Liao
Ren-Jye
RJ
Lee
Maw-Rong
MR
Lee
Thomas W
TW
Vickroy
Chi-Chung
CC
Chou
D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002523:Edible Grain / Q000737:chemistry* / Q000382:microbiology; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005506:Food Contamination / Q000032:analysis; D005658:Fungi / Q000378:metabolism*; D006801:Humans; D057230:Limit of Detection; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D015025:Zearalenone / Q000032:analysis*; D015029:Zeranol / Q000032:analysis*
D015025:Zearalenone; D015029:Zeranol