Abstract: A liquid chromatography-atmospheric pressure photoionization-mass spectrometry method was developed for thedetermination of chloramphenicol antibiotics in fish meats. For the optimization of APPI, several ion source parameters wereexamined. Using the optimized parameters, simple mass spectra and a strong signal corresponding to [M-H]- was observed. Thesamples were extracted with ethylacetate and evaporated to dryness followed by a clean-up step using liquid-liquid distributionby acetonitrile and n-hexane. Mean recoveries of chloramphenicol from young yellowtail meat and flatfish meat spiked at 0.1～2 ng/g were 89.3%～102.5% and 87.4%～94.8%, respectively. The limit of detection (signal-to-noise =3) of the young yellow-tail meat and the flatfish meat were 0.27 and 0.10 ng/g.

Key words: liquid chromatography-atmospheric pressure photoionization-mass spectrometry method, chloramphenicol antibiotics, ion source parameters