Content area
Full text
Anal Bioanal Chem (2013) 405:86338643 DOI 10.1007/s00216-013-7262-x
RESEARCH PAPER
Determination of avilamycin as dichloroisoeverninic acidin poultry and porcine muscles by isotope dilution liquid chromatographytandem mass spectrometry
Clare Ho & Yiu-Tung Wong
Received: 26 March 2013 /Revised: 4 July 2013 /Accepted: 15 July 2013 /Published online: 22 August 2013 # Springer-Verlag Berlin Heidelberg 2013
Abstract Avilamycin residue in food is regulated as its marker residue dichloroisoeverninic acid (DIA). An isotope dilution liquid chromatographytandem mass spectrometry method is established for the accurate determination of DIA in animal muscles without any pre-extraction and preconcentration prior to alkaline hydrolysis. Optimization of the sample cleanup procedures such as liquidliquid extraction and solid phase extraction was performed by fine-tuning several critical parameters to reduce the matrix effects. Quantification of DIA in edible muscle was accomplished by using matrix-matched calibration with dichloroisoeverninic acid-d6 as internal standard. The method was validated with DIA and avilamycin-fortified poultry and porcine muscles at three different levels (25, 50, and 100 g/kg). Conversion of avilamycin to DIA by alkaline hydrolysis was 92 %. The recoveries of DIA in both muscles at three fortification levels ranged from 94 to 106 % and RSDs were 11 % in all cases. The estimated limit of detection values in poultry and porcine muscles were 2.7 and0.7 g/kg, respectively. The estimated limit of quantitation values in poultry and porcine muscles were 8.3 and 2.4 g/kg, respectively. This method is suitable for routine monitoring of avilamycin residue in food safety surveillance programs.
Keywords Anionic mixed-mode solid phase extraction .
Avilamycin . Dichloroisoeverninic acid . Isotope dilution tandem mass spectrometry
Introduction
Avilamycin (Fig. 1) is a mixture of oligosaccharides of orthosomycins produced by Streptomyces viridochromogenes, with a linear heptasaccharide chain linked to a terminal dichloroisoeverninic acid (DIA) unit [1, 2]. Avilamycins A (60 %) and B (<18 %) are the major factors which contribute at least 70 % of avilamycin in the mixture [1]. Avilamycin is intended for use as a veterinary drug in chickens, turkeys, pigs, and rabbits to control bacterial enteric infections and is active against gram-positive bacteria, including Clostridium perfringens. [3]. It blocks the formation of the 70S initiation complexes in bacterial protein synthesis by inhibiting the binding of formylmethionine transfer ribonucleic acid to the 30S or 50S ribosomal subunit [46]....