UHPLC-MS/MS Determination of 13 Antibiotics in Water with Separation by Solid Phase Extraction

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%.