Sensitivity of Detection of 12 Aminoglycoside Antibiotics by Positive ESI - Comparison between HILIC and Reversed-Phase Methods

摘要

Structural differences that exist between 11 studied compounds resulted in ionization differences in the presence of ion pair reagent HFBA. The heavier compounds with more ionizable groups in their structure showed improved ionization efficiency in the presence of HFBA, which may be the result of the improved stability of the charged species. The lighter compounds ionized better without HFBA likely due to the ionization suppression effect of the ionpair agent. Post column infusion of the volatile ion pair agent improved linearity indicating that the ion pair agent contributed to more efficient ionization. The preferred chromatographic method for heavier aminoglycosides including neomycin, gentamicin and tobramycin is RP with HFBA ion pair when significant gains in sensitivity of detection by LC-MS/MS are needed. The preferred chromatographic condition for lighter compounds puromycin, spectinomycin and streptomycin is HILIC to achieve the lowest limits of detection.