固相萃取-高效液相色谱法测定畜禽粪便中罗红霉素和3种四环素类抗生素

Simultaneous determination of roxithromycin and three tetracyclines in manure by high-performance liquid chromatography with a diode-array detector

建立了固相萃取-高效液相色谱检测鸡粪和牛粪中的罗红霉素、土霉素、四环素和金霉素4种抗生素的分析方法。采用15mL EDTA—Mcllvaine缓冲液超声萃取15min，萃取液浓缩后经HLB固相萃取柱净化，甲醇洗脱，洗脱液浓缩定容后用HPLC进行检测。实验结果表明，测定罗红霉素的线性范围为1．5～600mg／L，土霉素、四环素和金霉素的线性范围为0．25—100mg／L，相关系数为0．9995～0．9999。畜禽粪便中4种抗生素的检出限为O．06～0．38mg/kg（S／N=3），定量限为0．2～1．2mg／kg（S／N=10）。基质加标回收率为52．2％-64．7％，相对标准偏差为7．3％～8．4％。

An analytical method for the simultaneous determination of roxithromycin, oxytetracycline, tetracycline and chlortetracycline in manure was developed by solid phase extraction and high-performance liquid chromatography with a diode-array detector. A centrifuged sample （2 g） was ultrasonically extracted with 15 mL of a mixture of EDTA and McIlvaine buffer （citric acid and sodium orthophosphate） for 15 min. Then the extract was evaporated and cleaned up on a HLB cartridge. The final eluate （methanol） was concentrated before injection. Using acetonitrile and 0. 03 mol/L ammonium dihydrogen phosphate （pH 2.0） as the mobile phase, roxithromycin was obtained good linear calibrations in the range of 1.5 - 600 mg/L, oxytetracycline, tetracycline and chlortetracycline were obtained good linear calibrations in the range of 0. 25 - 100 mg/L. And the correlation coefficients were 0. 9995 - 0. 9999, respectively. The limits of detection （LOD） and the limits of quantification （LOQ） were 0.06 - 0.38 mg/kg （ S/N = 3 ） and 0.2 - 1.2 mg/kg （ S/N = 10） in manure, respectively. The average recoveries were in the range of 52. 2% -64.7% when the spiked concentrations were 15 mg/kg roxithromycin, 2. 5 mg/kg oxytetracycline, tetracycline and chlortetracycline. The RSD ranged from 7.3% to 8.4%. This method is accurate, rapid and sensitive during the inspection of antibiotics in real samples.