Development and validation of a LC-MS/MS method for the determination of isoeugenol in finfish.

A simple, rapid, selective and sensitive LC-MS/MS method was developed and validated for the determination of isoeugenol in finfish using an off-line dansylation derivatization step to enhance signal intensity. The sample was extracted with 10mL acetone using a tissue homogenizer, followed by derivatization with dansyl chloride and analysis by liquid chromatography tandem mass spectrometry. The method detection limit ranged from 0.2 to 0.7ngg in six fish species. The limit of quantification was 2.5ngg in each species. Recoveries of isoeugenol at three different levels (5, 10 and 20ngg) over two different days ranged from 91.2% to 108.0%. Precision (%RSD) values determined at 10ngg were 4.3%, 8.0%, 5.3%, 5.1%, 2.6% and 8.0% for tilapia, catfish, trout, salmon, hybrid striped bass and yellow perch, respectively. Studies of linearity in the range 2.5-40ngg produced determination coefficients (R) above 0.997 for all matrices.