On-line Identification of chiral ofloxacin in milk with an extraction/ionization device coupled to Electrospray Mass Spectrometry

We built a simple and universal sample extraction/ionization device for on-line analysis of chiral ofloxacin in milk via Electrospray Mass Spectrometry (ESI-MS). Using electrospray ionization MS2 with kinetic method, quick qualification and quantification of ofloxacin enantiomers was realized by adding central metal ions and reference ligands in the extraction solution to form mass-selected trimetric cluster ions by electrospray ionization. This strategy greatly simplified the detection procedures of extraction, reaction agent mixing and ionization with total detection time less than 10 s137