Derivatization and Solidification of Floating Dispersive Liquid‐phase Microextraction for the Analysis of Kanamycin in Wastewater and Soil by HPLC with Fluorescence Detection

The abuse and uncontrolled discharge of kanamycin may result in potential risks to human health through food chain or environmental residues. Hence, the determination of kanamycin in various matrices is necessary. A sensitive and simple dispersive liquid–liquid microextraction based on solidification of floating organic droplet (DLLME-SFO) method has been developed for monitoring kanamycin in environmental samples. The method of DLLME-SFO after derivatization is coupled with high performance LC with fluorescence detection. The comparison was carried out between the staged and one-step procedure. The results indicated that the fluorescence derivatization reaction with 9-fluorenylmethyl chloroformate should be performed prior to extraction. The derivatization and DLLME-SFO conditions were optimized, respectively. Under the optimal conditions, the proposed method presented good linearity with square correlation coefficient of 0.9934, good reproducibility with relative standard deviations less than 9.6%, and the recoveries of kanamycin ranged from 91.3 to 102.7% for wastewater, and from 90.3 to 107.7% for soil. Furthermore, the detection limit was observed as 0.012 ng/mL. The proposed method was successfully applied to determine low levels of kanamycin in wastewater and soil samples.