固相萃取-亲水作用色谱法测定废水中四环素类抗生素

Solid Phase Extraction-Hydrophilic Interaction Chromatographic Determination of Tetracycline Antibiotics in Wastewater

建立了固相萃取(SPE)-亲水作用色谱法(HILIC)测定废水中金霉素(CTC)、强力霉素(DC)、四环素(TC)和土霉素(OTC)4种四环素类抗生素(TCs)残留的新方法。水样经Oasis HLB固相萃取柱净化富集后,采用以氨基色谱柱及高极性有机溶剂-水相缓冲溶液为流动相的亲水作用色谱法(HILIC)进行分析。对流动相中缓冲溶液的类型和pH值、离子强度、有机溶剂的浓度以及流速进行了优化,确定了以V(乙腈)∶V(6.7 mmol/L柠檬酸铵缓冲溶液,pH4.0)=85∶15混合液为流动相的最佳条件。本方法具有良好的线性关系(r>0.999)和重现性(峰面积RSD<1.0%),最低检出限(S/N=3)为12～30μg/L,4种四环素类药物添加水平在0.5～10μg/L范围内的标准加入回收率为90.6%～106.5%;相对标准偏差为2.5%～6.2%。本方法简便、准确、流动相离子强度低,适合于与质谱联用,用于屠宰场污水及医院污水等实际样品检测,结果满意。

A novel method for the determination of tetracycline antibiotics （TCs）, i. e. oxytetracycline （ OTC）, tetracycline （ TC）, chlortetraeycline （CTC） and doxycycline （DC） in wastewater sample by hydro- philic interaction chromatography（HILIC） using amino-silica column with highly polar organic-aqueous buffer as mobile phase has been developed. TCs were collected and purified from wastewater using Oasis HLB cartridges. Separation parameters such as the buffer pH, buffer ionic strength, organic modifier concentration and flow rate have been optimized. The optimal mobile phase was 85% （V/V） aeetonitrile in 6.7 mmol/L ammonium citrate buffer（pH 4.0）. The developed method had good linearity（r 〉 0. 999） and reproducibility （RSD 〈1.0% for the peak area）. The limits of detection for the TCs tested were between 12 -30 μg/L （S/N =3）. Recoveries of TCs at the concentration of 0.5 - 10μg/L ranged from 90.6% to 106.5% with RSD 2.5% -6.2%. The proposed method is simple, accurate and the mobile phase is compatible for mass spectrometry due to its low ionic strength. It has been applied to the determination of TCs in abattoir wastewater samples with satisfactory results.