Therefore, the introduction of the cationic dye (MB+) in the aqueous medium results in an increasing electrostatic repulsion with the positively charged nanoparticles (M-OH2+), thus resulting in a low adsorption rate of MB entities onto the active adsorption sites of the adsorbent. On the ...
However, the last two possibilities were ruled out as the signals were detected in various tested solvents using various MS ion sources (atmospheric pressure chemical ionization, electrospray ionization, and photoionization). Thus, the most likely explanation was the acidic nature of the compounds. ...