Determination of malachite green and leucoma - lachite green in trout and carp muscle by liquid chromatography with visible and fluorescence detection
2007
Bajc, Z., Ljubljana Univ. (Slovenia). Veterinary Fac. | Doganoc, D.Z. | Sinigoj-Gacnik, K.
A fast and specific method for determination of malachite green (MG) and its major metabolite leucomalachite green (LMG) in trout and carp muscle is described. MG and LMG residues were extracted from fish muscle with an ac- etonitrile-buffer mixture and isolated by partitioning into dichloromethane. Extracts were then cleaned up on solid-phase extraction (SPE) columns. Chromatographic separation was achieved by using reverse-phase column with an isocratic mo- bile phase consisting of acetonitrile and acetate buffer (0.01M, pH 4.1). MG was detected with an absorbance detector (λ= 618 nm), while a fluorescence detector (λex = 265 nm and λem = 370 nm) was used for detection of LMG. Both detec- tors were connected on-line which allowed simultaneous analysis of a sample extract for MG and LMG. The method was validated according to Commission Decision 2002/657/EC. The mean recoveries of MG and LMG from muscle fortified at three levels (2, 3, 4 μg/kg) were 55% and 74%, respectively. Relative standard deviations of the mean at all fortification levels were less than 15% and 13% for MG and LMG, respectively. With the described method 33 samples of fish bought in local shops and fish farms between August 2004 and April 2005 were analysed. Seven samples showed detectable amounts of residues.
显示更多 [+] 显示较少 [-]