抄録
An analytical method using HPLC was developed to analyze residual oxytetracycline (OTC) in apple juices. Residual OTC was
extracted with a citrate-phosphate buffer containing EDTA-2Na. The matrix was removed from the extract by a solid-phase column,
InertSep PLS-2 (265 mg/20 mL). After removing the solvent, the extract was resolved in a potassium phosphate solution. OTC in
the test solution was determined quantitatively using HPLC with a photodiode array detector (PDA). The interfering peaks were not
observed in chromatograms of blank extracts, indicating the high selectivity of this method. The limit of quantification of this method
was 0.01 µg/g in apple juices. Method validation was performed by recovery tests at 0.2 µg/g to evaluate the trueness, repeatability
(RSDr), and with-in laboratory reproducibility (RSDwr). The validation results for two types of apple juice exhibited sufficient
recovery (99% and 85%) and precision (RSDr ≦ 4% and RSDwr ≦ 5%). The time required for the preparation of eight test solutions
was less than three hours. This method can help inspect residual OTC in apple juices.
