Multiresidue determination of 21 pharmaceuticals in crayfish (Procambarus clarkii) using enzymatic microwave-assisted liquid extraction and ultrahigh-performance liquid chromatography-triple quadrupole mass spectrometry analysis

Chromatographic and MS parameters, in both positive and negative ionization modes, were also optimized. The mobile phase used consisted on a mixture of 0.1% (v/v) formic acid aqueous solution and acetonitrile in gradient elution mode at a 0.4 mL min−1 flow rate. The proposed method was validated and recoveries over 70% were obtained for all the analytes with detection limits in the 0.6-12 ng g−1 range. The proposed method was successfully applied to crayfish specimens from Doñana National Park, Spain.