采用固相萃取-超高效液相色谱-串联质谱法测定水中13种抗生素的含量。水样中的抗生素富集于PLS固相萃取柱上，用甲醇洗脱，洗脱液进行LC分离，以Endeavorsil C₁₈色谱柱为分离柱，以不同体积比的0.4%（体积分数）甲酸-水溶液和甲醇-乙腈（40+60）溶液的混合液为流动相进行梯度洗脱。质谱分析中，采用电喷雾正离子源多反应监测模式检测。13种抗生素均在一定的质量浓度范围内与其对应的峰面积呈线性关系，方法的检出限（3S/N）在0.4~1.5 ng·L^-1之间。以空白样品为基体进行加标回收试验，所得回收率在70.4%~101%之间，测定值的相对标准偏差（n=5）在1.1%~4.8%之间。

UHPLC-MS/MS was applied to the determination of 13 antibiotics in water with solid phase extraction. The antibiotics in water sample were enriched on PLS solid phase extraction column, and then eluted with 5 mL of methanol. LC separation was performed by using Endeavorsil C₁₈ chromatographic column as stationary phase, and the mixture of 0.4% (φ) formic acid solution and methanol-acetonitrile (40+60) solution with various ratios as mobile phase in gradient elution. ESI⁺ and multi-reaction monitoring were adopted in MS/MS. Linear relationships between values of peak area and mass concentration of the 13 antibiotics were kept in definite ranges, with detection limits (3S/N) in the range of 0.4-1.5 ng·L^-1. On the base of blank sample, test for recovery was made by standard addition method; values of recovery found were in the range of 70.4%-101%, with RSD's (n=5) in the range of 1.1%-4.8%.