分散固相精製を用いたシナモン中オキシテトラサイクリンの残留分析法の開発

抄録

The residual oxytetracycline analysis in cinnamon by dispersive solid-phase extraction using high-performance liquid chromatography (HPLC) was developed and validated. Oxytetracycline was extracted using McIlvaine buffer containing ethylenediaminetetraacetic acid (EDTA-2Na). The removal of matrix components derived from cinnamon was carried out using hexane distribution, solid-phase column extraction, and dispersive solid-phase extraction with Z-sep (zirconia-coated silica gel). After the removal of the solvent, the extract was dissolved in a potassium phosphate solution and analyzed by HPLC with a photodiode array detector (PDA). An interfering peak was not observed in the cinnamon extract chromatograms, indicating the high selectivity of this method. Method validation was performed by recovery tests at the maximum residue limit (MRL) concentration (0.1 µg/g) to evaluate the trueness, repeatability (RSD_r), and with-in laboratory reproducibility (RSD_wr). The validation results exhibited sufficient recovery (range, 79-81%) and precision (RSD_r ≤ 5% and RSD_wr ≤ 7%). These values fulfilled the criteria for the validation guidelines for residual pesticide analysis in Japan. The limit of quantification (LOQ) of this method was 0.03 µg/g in Chinese and Ceylon cinnamon. The time required for the preparation of eight test sample solutions was less than four hours. This method can help inspect residual oxytetracycline in cinnamons.