Fig. 1

Typical chromatograms obtained via fluorescence-based (excitation at 260 nm, emission at 315 nm) detection of colistin. a Blank serum, b serum sample containing 0.10 μg/mL colistin, c serum sample containing 4.0 μg/mL colistin, and d plasma sample obtained from a haemodialysis patient. Peak I = netilmicin, peak II = colistin B, and peak III = colistin A