Taking into account the intensity of the signal, a decrease in the concentration of imidacloprid and its derivatives can be observed with treat-ment time. The final analysis of samples after 24 h of treatment indicated the complete removal of any compounds. As shown in Fig. 5, the imidacloprid degradation profiles from EF-FeAB under higher pH values were much slower. The LC–MS studyalso allowed for the identification of two intermediates at pH 7(Table 1 (6) nitroso derivative and (7) olefinic cyclic guanidine)that are not present at pH 2 because of its faster degrada-tion.