Determination of mitoxantrone in environmental waters: a spectrophotometric method with preconcentration by salt saturated pipette-tip micro solid phase extraction using molecularly imprinted polymer

In this research, a fast and simple spectrophotometric method is presented for mitoxantrone determination in various aqueous samples. It utilizes preconcentration by salt saturated pipette-tip micro solid phase extraction with a selective molecularly imprinted polymer adsorbent packed in a micropipette tip. Prior to sample loading, they were saturated with a mixture of NaCl, Mg (NO₃)₂.6H₂O and KNO₃ salts, enhancing extraction efficiency by 27.5% compared to salt-free conditions. Key microextraction parameters (amount of molecularly imprinted polymer, sample pH, eluent type/volume, and adsorption/desorption cycles) were optimized using response surface methodology and one-variable-at-a-time methods. The method achieves a low detection limit (0.2 μg L^-1) and a wide linear range (1-1000 μg L^-1). An enrichment factor of 49 is obtained with excellent accuracy (relative standard deviation <4.4%). The method was validated by comparing it to a standard high performance liquid chromatography protocol, as well as spiking real samples in three concentration levels. The method successfully detected low levels of mitoxantrone in various water samples.