高效液相色谱法同时检测乳制品中3种β-内酰胺酶抑制剂的残留量

建立了乳制品中3种β-内酰胺酶抑制剂克拉维酸钾、他唑巴坦和舒巴坦的提取和固相萃取净化方法。样品经水溶后,用丙酮沉淀蛋白质。上清液在弱酸性条件下用PWAX固相萃取小柱(60 mg/3 mL)富集、净化,0.05%(如无特殊说明均为体积分数)氨水-甲醇溶液洗脱。然后采用高效液相色谱-二极管阵列检测器(HPLC-PAD)分离检测。分析柱为资生堂CAPCELL PAK MG-C18(150 mm×4.6 mm,5μm);流动相为0.03%磷酸-乙腈。该方法对克拉维酸钾、他唑巴坦和舒巴坦的最低检测质量浓度均为0.03 mg/L;纯牛奶、酸奶和奶粉中的回收率在84.6%~101.7%之间,RSD在2.2%~7.4%之间(n=6);在0.05~5 mg/L范围内均呈良好的线性关系,线性回归系数r>0.999。该方法的前处理净化效果好、检测灵敏度高、回收率和重现性良好,适用于乳制品中β-内酰胺酶抑制剂的测定。

Simultaneous determination of three β-lactamase inhibitor residues in dairy products by high performance liquid chromatography

An improved method has been developed for the determination of clavulanate potassium, tazobactam and sulbactam in dairy products. High performance liquid chromatography with photodiode array detector (HPLC-PAD) was used in this method. The separation was performed on a CAPCELL PAK MG-C₁₈ column (150 mm×4.6 mm, 5 μm). The mobile phase was 0.03% (volume fraction unless otherwise specified) phosphate-acetonitrile. This method offered effective sample preparation procedures including dissolution with water, protein isolation with acetone, clean-up and enrichment by solid-phase extraction (SPE) with PWAX cartridges (60 mg/3 mL) under weak acidic condition and further elution with 0.05% ammonia-methanol solution. The analytical method was well validated and good results were obtained with the RSDs of 2.2%-7.4% and the recoveries of 84.6%-101.7%. The detection limits of clavulanate potassium, tazobactam and sulbactam were 0.03 mg/L. All of the target compounds exhibited good linearities (r>0.999) over the mass concentration range of 0.05-5 mg/L. With the advantages of good purification effect, high sensitivity, good recovery and repeatability, the method is suitable for the detection of β-lactamase inhibitors in dairy products.