Determination of 6 Common Antibiotics Residues in Duck Intestine and Its Products by UHPLC-MS/MS after Ultrasonic Extraction and GPC Purification

A method was established for the determination of 6 common antibiotic residues in duck intestine and its products by ultra high pressure liquid chromatography triple quadrupole-mass spectrometry (UHPLC-MS/MS) after ultrasonic extraction and gel permeation chromatography (GPC) purification. The samples (12.0 g) were placed into a 50 mL plastic centrifuge tube after the duck intestines or its products were crushed, and 30 mL of methanol, 1.0 mL of ammonia water and 3.0 g of anhydrous sodium sulfate as dehydrant were followed. The samples were homogenized for 1 min, extracted by ultrasonic for 15 min, and refrigerated for 6 min. The supernatant was all transferred to the GPC purification bottle and purified under the GPC conditions. The collected eluent was put into a nitrogen blower and blown to nearly dryness by nitrogen. The residue was dissolved with 1 mL of methanol and filtered through a 0.45 μm membrane. The filtrate was qualitatively and quantitatively detected by UHPLC-MS/MS. The results showed that linear relationships between values of peak area and mass concentration of temicocacin, roxithromycin, erythromycin, ofloxacin, ciprofloxacin and florfenicol were found in the range of 0.01-10.00 mg·L^-1, with detection limits (3S/N) of 0.221, 0.153, 0.396, 0.112, 0.577, 0.089 μg·kg^-1, respectively. Test for recovery was made by standard addition method, giving results in the range of 82.4%-107%, with RSDs (n=6) of the determined values less than 5.0%.