Introduction

　　There is a growing concern over the presence of antibiotics in environmental sources of water.This has caused environmental and government labs to develop LC/MS methods to monitor water supplies for the presence of antibiotics.However,the low-level concentration of antibiotics in environmental water sources often requires extensive sample preconcentration and cleanup.

　　Goal

　　Develop a method to screen for antibiotics in surface water by applying on-line preconcentration and analyte extraction with LC/MS/MS detection.

　　instrument:

　　TSQ Quantum Ultra

　　Conclusions

　　A method for assaying antibiotics in water sample at the lolw pg/ml level using on-line sample clean-up and preconcentration has been demonstrated.