抄録
An analytical method that uses LC-MS/MS was developed for the analysis of clenbuterol residue in pork muscle and processed
pork food. The method was evaluated by conducting recovery tests according to the guidelines for validation of analytical methods
by the Ministry of Health, Labour and Welfare of Japan. Samples were initially extracted with acetonitrile, anhydrous sodium
sulfate, and sodium chloride. The extracts were subjected to dispersive solid-phase extraction (dSPE) based on C18 substrate
and PSA cartridge column SPE. PSA effectively removed residual fatty acids and other interferences remaining in the extracts.
Clenbuterol in the purified solution was determined quantitatively using LC-MS/MS. The recoveries of clenbuterol fortified at
0.05 ng/g in pork muscle and processed pork food were examined. For pork muscle and processed pork food measured by the
matrix calibration curve method, accuracy (trueness) was 93.4% and 92.4%, repeatability was 3.0% for both, and within-laboratory
reproducibility was 8.4% and 13.2%, respectively. For pork muscle and processed pork food measured by the internal standard
method, accuracy (trueness) was 100.1% and 97.2%, repeatability was 5.1% and 2.8%, and within-laboratory reproducibility was 5.7%
and 3.7%, respectively. These results indicate that both the matrix calibration curve method and the internal standard method meet
the target values stated in the guidelines. Whereas the analytical method developed in this study is adequate for measuring current
regulation levels of residues, in the examination of various types of processed food, such as processed pork food that requires
different matrices, quantification by the internal standard method is likely to be more practical and desirable.
