Study on the enhanced fluorescent spectrum of ciprofloxacin + Al(III) + La(III) + cetyltrimethylammonium bromide system and its application

The fluorescence of ciprofloxacin (CIP) in HAc–NaAc buffer solution and the presence of cetyltrimethylammonium bromide (CTMAB) enhanced visibly with adding Al(III) and La(III). This enhanced fluorescence spectra were studied, and a new co-luminescence system of CIP + Al(III) + La(III) + CTMAB was discovered. There was a linear relationship between the enhanced fluorescence intensity and the concentration of CIP in the range of 0.50–80.2 μg l−1 under the optimized condition. A novel enhanced fluorescence method for the determination of trace CIP was established by using this co-luminescence system. The detection limit of the proposed method was 0.17 μg l−1 for CIP. This method is simple, rapid and sensitive. The CIP in milk samples were analyzed by the proposed method with satisfactory results. The relative standard deviation and the recovery were in ranges of 3.21–4.34% and 97.1–100.1%, respectively. The mechanism of the co-luminescence reaction and the reasons for fluorescence enhancement has been discussed.