取500 mL废水样品,用6 mol·L^-1盐酸溶液调节溶液酸度至pH 2.0~4.0后,再加入150 mg抗坏血酸和250 mg乙二胺四乙酸二钠。采用HLB固相萃取柱富集净化,用10 mL甲醇分两次洗脱。将洗脱液氮吹至近干,加入25 μL内标溶液,用初始比例流动相定容至1.0 mL,经0.22 μm有机滤膜过滤,得待测液。以ZARBAX Eclipse Plus C₁₈色谱柱为固定相,以不同体积比的甲酸-甲醇-乙腈-水的混合液为流动相进行梯度洗脱。质谱分析采用电喷雾正离子(ESI⁺)源和多反应监测(MRM)模式检测,内标法定量。结果显示:12种抗生素标准曲线的线性范围均为2.00~200 μg·L^-1,检出限(3.143s)为0.001~0.007 μg·L^-1;对空白样品进行3个浓度水平的加标回收试验,回收率为60.1%~125%,测定值的相对标准偏差(n=6)为2.8%~13%。方法用于实际水样分析,结果显示5个不同来源的水样中均不同程度地检出抗生素。

Waste water sample (500 mL) was adjusted to pH 2.0-4.0 with 6 mol·L^-1 hydrochloric acid solution, and 150 mg of ascorbic acid and 250 mg of ethylenediamine tetraacetic acid disodium were added. HLB solid phase extraction column was used for enrichment and purification, and 10 mL of methanol was used for elution twice. The eluate was dried by nitrogen blowing and internal standard solution (25 μL) was added. The solution was made its volume up to 1.0 mL with initial proportional mobile phase and filtered by 0.22 μm microporous membrane for test. ZARBAX Eclipse Plus C₁₈ chromatographic column was used as the stationary phase, and a mixture of formic acid, methanol, acetonitrile and water at different volume ratios was used as the mobile phase for gradient elution. ESI⁺ and MRM mode were used in MS analysis, and internal standard method was used for quantitative analysis. As shown by the results, the linear ranges of standard curves for 12 antibiotics were all 2.00-200 μg·L^-1, with detection limits (3.143s) in the range of 0.001-0.007 μg·L^-1. Recovery test was made on the blank sample at 3 concentration levels by standard addition method, giving results in the range of 60.1%-125%, and RSDs (n=6) of the determined values were in the range of 2.8%-13%. This method has been applied to the analysis of actual water samples, and the results showed that antibiotics were detected in 5 water samples from different sources in varying degrees.