提出了固相萃取富集-高效液相色谱-串联质谱法测定饮用水源水体中8种抗生素残留量的方法。样品按规定方法进行预处理并调节其酸度至pH 2.5或pH 3.2。将此溶液经过Oasis HLB SPE小柱进行富集并净化。用XBridge C18色谱柱为分离柱,以不同体积比的(A) 10 mmol·L-1甲酸溶液和(B) 10 mmol·L-1甲酸-甲醇溶液组成的混合液作流动相进行梯度淋洗。串联质谱分析中采用电喷雾正、负离子源及多反应监测模式。8种抗生素的质量浓度均在1.00~400 μg·L-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.4~0.7 ng·L-1之间。加标回收率在81.9%~110%之间,测定值的相对标准偏差(n=7)在0.7%~4.5%之间。

A method of HPLC-MS/MS for the simultaneous determination of residual amounts of 8 antibiotics in water sample from drinking water source with enrichment by solid phase extraction was proposed. The pretreated water sample was adjusted to pH 2.5 or pH 3.2, and was passed through the Oasis HLB SPE microcolumn for enrichment and purification of the analytes. XBridge C18 chromatographic column was used as stationary phase, and the mixture of (A) 10 mmol·L-1 formic acid solution and (B) 10 mmol·L-1 formic acid-methanol solution in different ratios was used as mobile phase in gradient elution. In MS/MS analysis, ESI+, ESI-and mode of multi-reaction monitoring were adopted. Linear relationship between values of peak area and mass concentration of the 8 antibiotics was kept in the same range of 1.00-400 μg·L-1, with detection limits (3S/N) in the range of 0.4-0.7 ng·L-1. Values of recovery measured by standard addition method were in the range of 81.9%-110%, with RSD′s (n=7) in the range of 0.7%-4.5%.