Quantitative Determination of Four Nitrofurans and Corresponding Metabolites in the Fish Muscle by Liquid Chromatography-Electrospray Ionization-Tandem Mass Spectrometry
CHUNG-WEI TSAI1, CHUAN-HO TANG1 AND WEI-HSIEN WANG1,2*
1 .Division of Marine Biotechnology, Asia-Pacific Ocean Research Center, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, R.O.C.
2 .National Museum of Marine Biology and Aquarium, Pingtung 944, Taiwan, R.O.C.
(Received: January 23, 2009; Accepted: February 7, 2010)
ABSTRACT
A method validated based on the European Union (EU) regulations for determining the presence of furazolidone, furaltadone, nitrofurazone, nitrofurantoin and their corresponding metabolites AOZ, AMOZ, SC and AH in fish muscle was developed. Samples were acid-hydrolyzed, treated with 2-nitrobenzaldehyde and extracted with ethyl acetate. The extracts were dried in a N2 stream and redissolved in methanol:water (50:50, v/v). Analysis was performed by LC/ESI/MS/MS. This developed method carried limits of quantification lower than 10 μg/kg for the nitrofurans and 1.0 μg/kg for the metabolites. It was observed that the decision limit (CCα) ranged from 2.93 to 5.01 μg/kg for the nitrofurans and 0.19 to 0.43 μg/kg for the metabolites. The detection capability (CCβ) was between 3.62 and 6.20 μg/kg for the nitrofurans and between 0.23 and 0.54 μg/kg for the metabolites. The linear calibration curve parameters in the fortified fish muscle were between 1.0-100.0 μg/kg and 0.1-10.0 μg/kg for the nitrofurans and metabolites, respectively.
Key words: nitrofuran, metabolite, LC-ESI-MS/MS